The Red List of 

Betulaceae

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International

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Recommended citation: Shaw, K., 

Stritch, L., Rivers, M., Roy, S., Wilson, B. 

and Govaerts, R. (2014) The Red List of 

Betulaceae. BGCI. Richmond. UK.

ISBN-10: 1-905164-58-0

ISBN-13: 978-1-905164-58-5

AUTHORS

All authors are members of the IUCN / 

SSC Global Trees Specialist Group

Kirsty Shaw is Conservation Officer at 

BGCI. 

Larry Stritch is a National Botanist at the 

USDA Forest Service.

Malin Rivers is Red List Manager at BGCI.

Shyamali Roy and Becky Wilson are 

interns at BGCI working on the Global 

Trees Campaign.

Rafaël Govaerts is Senior Checklist 

Compiler at the Royal Botanic Gardens, 

Kew and facilitates the compilation and 

peer-review of the World Checklist of 

Selected Plant Families.
The Red List of 

Betulaceae

Kirsty Shaw, Larry Stritch, Malin Rivers, Shyamali Roy, 

Becky Wilson and Rafaël Govaerts 

2014
The Red List of Betulaceae

2

Contents

Acknowledgements 3

Acronyms 3

Foreword 4

Introduction 5

Distribution 5

Information Collection for Conservation Assessment 6

Results of the Evaluation 7

Conservation and Research Priorities 8

References 13

Globally Threatened Betulaceae TAXA 15

Betulaceae Taxa Evaluated as Data Deficient 32

Betulaceae Taxa Evaluated as Least Concern 37

References 54

Annex I

IUCN Red List Categories and Criteria (Version 3.1) 65
The Red List of Betulaceae

3

The authors would like to thank 

the many experts from the 

around the world who contributed information and have undertaken 

assessments for this global evaluation 

of Betulaceae taxa.

Members of the IUCN/SSC Global 

Tree Specialist Group and the BGCI 

network were particularly helpful in 

providing information on taxa present 

in their particular regions and facilitating 

the involvement of additional experts. 

Particular thanks go to Dr. Sudipto 

Chatterjee (TERI University, India) for 

providing information on Himalayan 

taxa. Thanks also Rebecca Hsu 

(Taiwan Forestry Research Institute) 

for assisting with the assessments of 

Taiwanese taxa. The authors would 

also like to thank Paul Bartlett (Stone 

Lane Gardens, UK) and members of 

the IUCN/SSC Caucasus Plant Red List 

Authority for providing information to 

support the assessments of taxa from 

the Caucasus region.

The authors are very grateful to Fondation Franklinia for supporting BGCI’s 

red listing work. Finally thanks to the 

United States Department of Agriculture 

(USDA) Forest Service for design work 

and printing of this report. 

List of Acronyms

AOO Area of occupancy

ASL Above sea level

BGCI Botanic Gardens Conservation International

EOO Extent of occurrence

FFI Fauna & Flora International

GIS Geographical Information System

GSPC Global Strategy for Plant Conservation

GTC Global Trees Campaign

GTSG IUCN/SSC Global Tree Specialist Group

IUCN International Union for the Conservation of Nature

SSC Species Survival Commission

SIS Species Information Service

USDA United States Department of Agriculture

Acknowledgements
The Red List of Betulaceae

4

The Betulaceae, the birches, 

alders, hazels, hornbeams, hop 

hornbeams and Ostryopsis, 

include some commercially important 

timber and nut producing trees. Several 

species of Betula are ecologically 

dominant in cold-temperate Northern 

Hemisphere forests and tundra, while 

some species of Alnus, Carpinus and 

Corylus form smaller pure stands or 

are major components of forest, scrub 

forest or forest understorey. In these 

more northern forests, to a large extent 

in formerly glaciated areas, there are 

no, or hardly any, relict endangered 

species. Other species of all genera 

are components of warm-temperate to 

tropical forests and relicts of the Arcto-Tertiary forests in which such species 

were much more prominent and widely 

distributed (Crane and Stockey 1987; 

Collinson 2000; Manchester and Tiffney 

2001). It is among these that we find 

the rare and threatened species, largely 

in the well known refugia on low latitude 

mountain ranges in Japan, Korea, south 

China and Taiwan, the Caucasus/

Caspian region, and southern parts of 

eastern North America.

This Red List report, the 10th in a series 

produced by the IUCN/SSC Global Tree 

Specialist Group, provides the results 

of a global conservation assessment 

for the family Betulaceae. It highlights 

the relatively small number of taxa that 

qualify as globally threatened using the 

IUCN Red List categories and criteria. 

In the Betulaceae the taxonomy in 

several genera is confused, so it can 

be difficult to determine conservation 

status. However, it should usually be 

possible to differentiate between very 

distinct paleoendemics deserving of 

conservation effort, and taxa which are 

probably minor variants of common, 

widely distributed species which will not 

usually justify significant conservation 

effort (Ashburner and McAllister 2013). 

In some cases mere forms (e.g. Betula 

oycoviensis and B. lenta f. uber) or 

minor variants of common species 

have been red listed in the past and 

considerable resources spent on their 

conservation, while equally distinctive 

populations have not been considered 

because they have not been named 

(e.g. the tetraploid Greek population 

of A. glutinosa). Lack of information on 

little known species, mainly from less 

studied parts of the world, is a major 

issue, and this list highlights these 

and should stimulate those cultivating 

such species to ensure they maintain 

breeding populations until certain that 

the wild populations are secure.

Ideally the taxonomy of Betulaceae 

would be resolved first, before deciding 

conservation priorities, but this can 

take a long time (Landrum, 2003), and 

it is essential that this Red List report 

is published sooner rather than later 

to draw attention to those species 

requiring attention. In this family some 

of these species may be of potential 

economic significance as well as being 

worthy of conservation for their own 

sake. This is likely to apply to species 

of Alnus because of their value in 

reclamation due to their nitrogen fixing 

properties. Some shrubby species (e.g. 

A. faurei, A. sieboldiana) seem to be 

much more drought tolerant than is 

usually realised and could be ideal as 

nurse species for timber trees. Alder 

species appear to be cross-compatible 

with respect to symbiont Frankia strains, 

all species developing effective nodules 

in UK soils.

Conservationists often insist that large 

populations are required to maintain the 

genetic diversity of a species but, with 

large woody plants, maintaining such 

living collections is often not possible except for species of value in forestry. Fortunately seed of species of Betulaceae 

is usually fairly long-lived in storage. 

Though inbreeding depression is always 

a potential problem (Kuser 1983; Coates 

1992; De Smet 1993), there are many 

instances where very small numbers 

of individuals have given rise to huge 

populations following introductions–as 

long as populations have been able to 

expand rapidly, lack of initial genetic 

diversity does not seem to have been 

a problem (Taggart et al. 1990; Meffert 

1999; Merilä 1996; Jackson, et al. 2004). 

Self-compatible inbreeders such as 

some rare Betulaceae may already have 

suffered the consequences of inbreeding but still survived, perhaps following 

purging of deleterious genes (Byers 

and Waller 1999). With rare species it is 

clearly essential with self-incompatible 

species, and probably desirable with 

self-compatible ones (Kuser 1983), that 

more than one clone is maintained in 

cultivation in a garden to ensure seed 

production. Far too many gardens 

grow single plants of such threatened 

species as curators try to find space for 

as many different species as possible. 

However, to conserve the genetic 

variation of variable species it certainly 

requires the survival of a larger number 

of individuals than can usually be 

maintained in cultivation, species often 

being represented in cultivation by a 

tiny fraction of their variation in the wild 

(Jeffrey, 1982, Brodie et al. 1998). This 

is why conservation of wild populations 

is always preferable where possible.

I hope that this report will stimulate 

increased conservation action for those 

species that are identified as globally 

threatened. At the same time we need 

to find more information for those that 

are recorded as Data Deficient. A combination of ex situ and in situ measures 

should ensure that no species of the 

Betulaceae becomes extinct.

Hugh McAllister, author The Genus 

Betula: A taxonomic revision.

Foreword
The Red List of Betulaceae

5

The Betulaceae family comprises trees 

and shrubs from six genera; Alnus (Alder), 

Betula (Birch), Carpinus (Hornbeam), 

Corylus (Hazel), Ostrya (Hop Hornbeam) 

and Ostryopsis. There are approximately 

166 species, the exact number of species 

and infraspecific taxa varying with taxonomic uncertainty. 

The largest genus is Betula. According 

to the recently published monograph for 

this species, there are 40–50 recognised 

species (Ashburner and McAllister, 2013), 

the World Checklist of Selected Plant 

Families recognises 62 species (Govaerts, 

2014). The smallest genus is Ostryopsis 

with only 3 recognised species. Further 

details on the taxonomy used for these 

assessments are presented on page 7. 

Betula and Alnus are closely related. Their 

chromosome numbers are multiples of 

14, but Carpinus, Ostrya and Ostryopsis are multiples of 8, and Corylus 11. 

Due to their distinctiveness from Betula 

and Alnus, the latter four genera were 

previously placed in a separate family: 

Corylaceae. There is now wide agreement 

to place them in the Betulaceae family.

Distribution

The Betulaceae family includes taxa distributed across a large proportion of the 

northern hemisphere, from Canada in the 

West to China, Japan and Siberia in the 

East. In northerly climes, dwarf varieties 

dominate, such as the Dwarf Birch Betula 

nana, found mainly in the Arctic tundra 

region. A few species spread south of the 

Equator, found in Central America and 

northern parts of Southern America.

The family comprises taxa that have large 

natural distributions and are common 

across their range, such as Betula pendula 

and Corylus avellana. However, some 

taxa are restricted to a very small area 

with low population numbers, the most 

restricted being known only from a single 

tree, as is the case for Carpinus putoensis.

The altitudinal range of the family is 0 m 

to approximately 4,500 mm ASL.

Introduction

Uses of Betulaceae

Ornamental value–A number of Betulaceae taxa are known for their ornamental value. Betula, for example, are valued by gardeners and landscapers 

and found widely in private and public gardens due to their attractive foliage, 

catkins, autumnal colours and bark. The bark of Betula trees sets them apart 

from other genera in the family and occurs in a variety of colours including 

white, and varying shades of pink, yellow, orange, red and brown. The bark 

can be shiny and peels from the trunk of some taxa. Popular cultivars include; 

B. pendula ‘Tristis’ (a weeping form with white bark), B. ermanii ‘Polar Bear’ 

(with white bark) and B. albosinensis ‘Pink Champagne’ (with pink/red bark).

Alnus have ornamental value for their attractive catkins and cones, and glossy 

foliage. They are also popular because they are hardy and can survive well 

in damp or wet sites. A. glutinosa, A. incana and A. cordata are the most 

common species found in cultivation. Some taxa, such as A. cordata, have 

spread readily from garden collections and have become well established 

beyond their natural range.

Carpinus species are popular for their attractive deeply ribbed leaves and are 

often used in hedging.

Hazelnut production–All Corylus taxa produce edible nuts, known as hazelnuts or cobnuts. They therefore provide a valuable food source to wildlife. 

The European hazelnut (C. avellana) is the most economically valuable of the 

Corylus taxa and is the only Corylus species that is cultivated for its nuts. It 

produces the highest quality nut and produces the greatest yield of all Corylus 

species. Hazelnuts from other species such as C. americana, C. heterophylla, 

C. jacquemontii and C. colurna are harvested from the wild and sold in local 

markets. 

The global market for C. avellana is dominated by Turkey which is the biggest 

worldwide producer, followed by Italy and the US (Molnar, 2011). In rural 

parts of the Black Sea region (including Turkey) hazelnut production is a 

key factor in maintaining social, economic and environmental sustainability. 

Although production of hazelnuts fluctuates yearly depending on climatic 

conditions, commercial production is increasing as a whole. The average 

farm-gate value of the U.S. crop in the past three years was about $63 million 

with a processed value of $160 million (USDA, 2012). The hazelnut economy 

directly and indirectly supports eight million people (Molnar, 2011).

Medicinal properties–Many species of the genera Alnus and Betula have 

been used as traditional herbal medicines. They have a wide variety of medicinal applications. Leaf teas were often used as a skin wash to soothe insect 

bites and skin irritations and also as a diuretic to treat urinary tract infections 

and as a treatment for rheumatism and gout (Tilford, 1997). Betula leaves 

have also been used on the scalp to reduce hair loss and dandruff and Betula

bark can be used to make a drink said to purify the blood (American Cancer 

Society, 2008). Some species, especially Betula lenta, contain methyl salicylate, 

(continued on next page)
The Red List of Betulaceae

6

or oil of wintergreen, which in the past 

was distilled from the twigs and used 

as an anti-inflammatory.

The bark of many Alnus and Betula

species contains the compounds 

lupeol and betulin which have been 

shown to be effective in fighting a 

variety of cancers, and scientists are 

now researching the potential use to 

treat the herpes virus, hepatitis and 

HIV-1 viral replication (Sati et al., 2011).

Timber–A number of Betulaceae taxa 

are used for timber. Species of particular economic importance for their 

timber include A. rubra, A. glutinosa

and B. pendula.

Birch timber is straight grained, strong 

and durable, making it useful for plywood and furniture. B. pendula and 

B. populifolia for example, are both 

grown for production of high quality 

plywood.

Alnus timber is very durable underwater, making it particularly useful for 

deep foundations of buildings and 

bridge poles. A. cordata for example 

has been used as foundation poles 

for houses in Venice.

The wood of Carpinus species has 

minor economic importance. It is a 

hardwearing wood and uses include 

mallet heads, tool handles and other 

small wooden objects. The timber 

also has attractive swirls in the grain 

and a smooth finish, making it very 

useful for furniture making.

Ostrya knowltonii and O. virginiana

are often used to make durable items 

such as fence posts and tool handles 

as their timber is hard and tough.

Other uses–A number of other uses 

exist, which have varied in economic 

and social importance over time. For 

example, sap extracted from birch 

trees, usually Betula lenta, B. pendula 

or B. papyrifera, can be drunk as a 

tonic, it can be fermented into Birch 

beer or wine or it can be concentrated 

to make a birch syrup. Birch tar is extracted from the bark using high temperatures and has been used as an 

adhesive in weapon and tool making, 

and in the repairing and waterproofing 

of ceramic vessels (Tiilikkala et al., 

2010). Birch tar is also an astringent 

ingredient in ointments for eczema 

and psoriasis (Stone Lane Gardens, 

2014).The papery bark from many 

birch species can be used to waterproof roofs, make canoes and in India 

it replaced parchment as the primary 

writing medium for manuscripts. The 

coppiced stems of Corylus had great 

economic importance in the past, used 

for basket making, thatching, wood 

fuel and wattles (Royal Forestry 

Society, 2014).

Over-exploitation of wild populations 

can pose a threat to Betulaceae taxa. 

Sustainable harvesting methods and 

replanting must be carried out to 

ensure human use of these ‘useful’ 

taxa does not threaten their survival 

in the wild. The most economically 

important Betulaceae taxa, including 

Betula pendula for timber and Corylus 

avellana for hazelnut production, are 

widely cultivated to supply demand.

Betulaceae taxa also play a valuable 

ecosystem role. White barked birches 

in particular are good pioneer species 

and can rapidly colonise cleared areas, 

preventing soil erosion and paving the 

way for re-establishment of previous 

forest cover. They are “regarded as 

the weed trees of the landscape” in 

northern latitudes (Ashburner and McAllister, 2013), but despite this seemingly negative assertion, it also highlights 

a great potential for the use of such 

species in reforestation and restoration 

projects. Many taxa can also withstand 

low nutrient levels, sandy soils and 

wet habitats, including bogs, thereby 

occupying ecological niches unsuitable for other tree species. 

The ability of many Betulaceae taxa to 

grow at high altitudes also means they 

serve a vital role in watershed protection and soil stabilisation. Conservation of wild populations is particularly 

important in highland areas so this 

important ecosystem service is not 

lost. Alnus species are nitrogen fixing, 

improving soil conditions and supporting growth of other species. Habitat 

conservation is essential to ensure 

the survival of Betulaceae taxa in the 

wild, and is of particular importance 

in low nutrient, highland and delicate 

ecosystems such as peat bogs.

Uses of Betulaceae (continued from previous page)

Information collection for

conservation assessment

This publication represents the first 

attempt to undertake a conservation 

assessment of all known taxa within 

the Betulaceae family. At the time of 

production of this work, only 15 Betulaceae species were published on the 

IUCN Red List of Threatened Species 

(IUCN Red List, www.iucnredlist.org), 

many of which were assessed in The 

World List of Threatened Trees (Oldfield, 

et al., 1998) and are now out of date. 

In this publication 240 up to date taxa 

assessments are presented.

Taxonomy

A complete taxonomic revision of the 

Betulaceae family has not been undertaken. It is important to note that it is not 

the intention of this publication to resolve 

taxonomic issues for Betulaceae taxa.

The recently published Betula monograph 

(Ashburner and McAllister, 2013) was a 
The Red List of Betulaceae

7

very valuable resource for this assessment. The assessments presented in 

this publication for Betula taxa follow 

the taxonomy presented by Ashburner 

and McAllister, with additional assessments presented for a small number of 

Betula taxa, recognised as accepted 

species but not verified by the authors 

of (and therefore not included in) the 

recent Betula monograph as they did 

not see any material. Taxonomy for 

other genera (and accepted Betula

taxa not included in the Ashburner 

and McAllister publication) follows 

The World Checklist of Selected Plant 

Species (http://apps.kew.org/wcsp/

home.do) (Govaerts, 2014).

Conservation assessments were undertaken for all accepted Betulaceae species 

in the Betula monograph and the World 

Checklist of Selected Plant Families. 

Assessments are also undertaken for 

accepted infraspecific taxa with varying 

distribution to the parent species. When 

an infraspecific taxon has a similar distribution, population and threat status to the 

parent species, a separate assessment 

is not presented for the infraspecific 

taxon. It was not attempted to undertake conservation assessments for all 

recognised infraspecific taxa, as very 

limited information is available and taxonomy is uncertain for many of these taxa.

Table 1 shows the number of species 

and insfraspecific taxa per genus assessed in this Red List report.

Information collection and 

assessment methodology

Assessments were undertaken using the 

IUCN Red List Categories and Criteria 

(version 3.1, see Annex I for details). Assessments presented here provide summary information of full assessments that 

have been undertaken and entered into 

the IUCN Species Information Service 

(SIS) for review and publication on the 

online IUCN Red List of Threatened Species. Full assessments were undertaken 

by Kirsty Shaw, Shyamali Roy and Becky 

Wilson from BGCI, Larry Stritch from the 

USDA Forest Service and supported by 

experts (see detail in individual assessments and acknowledgements section).

Information was collected from published 

literature, including national flora, national 

Red Data books and journal articles. To 

supplement this, herbarium specimen 

databases, online plant information databases, including Tropicos, NatureServe, 

The Plant List, and other online data from 

reputable sources, were also consulted. 

A full reference list for the assessments 

is presented on pages 54 - 64.

In addition to a thorough review of available literature, experts were contacted 

to obtain and verify information for the 

taxa assessed. Experts were identified 

through the BGCI network and the IUCN/

SSC Global Tree Specialist Group (GTSG) 

and authors of consulted literature were 

also contacted. This communication is 

referenced as pers. comm.

This publication includes distribution 

maps for threatened taxa. As most 

threatened taxa are known only from 

a single or small number of localities 

and small population numbers, maps 

are presented as point data rather than 

polygons. Distribution maps could not 

be produced for Data Deficient taxa as 

data points are not available for many 

of these taxa. Maps are not included for 

Least Concern taxa in this report. 

Results of the Evaluation

240 Betulaceae taxa have been assessed; 

166 species and 74 infraspecific taxa 

(subspecies and varieties). 

The results of the assessments are summarised in Table 2. This indicates that 

of the 240 Betulaceae taxa assessed, 

only 16 are threatened with extinction in 

the wild according to the IUCN Red List 

Categories and Criteria (Critically Endangered, Endangered and Vulnerable).

Genus No. of species 

assessed

No. of infraspecific taxa 

assessed

Total no. of taxa 

assessed

Alnus 38 20 58

Betula 60 19 79

Carpinus 40 23 63

Corylus 16 10 26

Ostrya 9 2 11

Ostryopsis 3 0 3

Total 166 74 240

Table 1: Number of species and infraspecific taxa per genus assessed 

in this Red List report

Conservation Status Number of 

Betulaceae 

taxa

Critically Endangered (CR) 11

Endangered (EN) 3

Vulnerable (VU) 2

Near Threatened (NT) 5

Data Deficient (DD) 83

Least Concern (LC) 136

Total 240

Table 2: Number of taxa per IUCN

category assessed in this report

An additional 5 taxa are assessed as 

Near Threatened. If action is not taken to 

address the threats facing the remaining 

populations of these taxa, they are likely 

to qualify within a threatened category in 

the near future.

A high number of taxa are assessed as 

Data Deficient, 83 taxa. There is taxonomic debate surrounding many of these 

taxa. There is a great need for further 
The Red List of Betulaceae

8

study to determine which of these are 

true taxa and to gather sufficient information to carry out full conservation 

assessments. Further information about 

Data Deficient taxa is presented on 

pages 32 - 36. 

A high number of taxa are assessed as 

Least Concern, 136 taxa. The majority 

of these taxa have wide distributions, and 

there are no known threats impacting 

these taxa to the extent that conservation action is required to ensure they do 

not become threatened in future. More 

information about the Least Concern 

taxa is presented on pages 37 - 53.

Conservation and Research

Priorities

This global assessment of Betulaceae 

can be used to guide future conservation action for these taxa. Urgent action 

is required for taxa assessed as Critically 

Endangered. The remaining populations 

of these taxa are very small. For example, 

the population of Ostrya rehderiana is 

reported to have reduced rapidly, there 

are only 5 remaining individuals in the 

wild and no conservation programme is 

reported to be in place for this species. 

Critically Endangered taxa are at great 

risk of extinction in the near future and 

conservation action must be increased 

to ensure the survival of all Critically 

Endangered taxa. 

Conservation action is also required for 

taxa assessed as Endangered, Vulnerable and Near Threatened. If the threats 

currently impacting on these species 

persist or worsen their populations will 

decline and the risk of extinction to these 

taxa will increase.

Globally threatened taxa are presented 

on pages 15 - 31.

In situ conservation (protection within the 

natural habitat of a taxon) should be a 

priority for threatened taxa. Target 7 of 

the Global Strategy for Plant Conservation (GSPC) calls for 75% of known 

threatened plant species conserved in 

situ by 2020. Some threatened taxa are 

reported to exist in protected areas, 

for example Ostrya chisosensis which 

occurs in Big Bend National Park, Oklahoma, U.S.A., and some are known to 

be subject to less formal in situ protection, such as the Critically Endangered 

Carpinus putoensis; the remaining individual of this species is located near a temple, 

is revered as an icon and is fenced with 

an information panel provided for visitors. 

However, in situ conservation action is 

not yet reported for many of the taxa 

listed as threatened here. 

In situ conservation efforts help to protect 

the habitat of the taxa and the flora and 

fauna that are part of the same ecosystem. In situ efforts are therefore a good 

long term conservation option. It is recommended that some level of in situ

protection be put in place for all taxa 

listed as threatened in this publication.

Ex situ conservation is well recognised 

as an important security measure against 

extinction, especially for taxa represented 

by very small wild populations. By ensuring taxa are represented in well-managed 

and secure ex situ collections, if wild 

populations are lost due to threats imposed by humans or natural disasters, 

the taxon will not be lost completely.

Call for action: Data Deficient taxa

A large number of taxa have been assessed as Data Deficient, 83 taxa. 

Although some information is available on the distribution of these species, 

very little or no additional information is available to carry out a full conservation assessment.

The majority of these taxa are reported to have limited ranges and there is 

taxonomic uncertainty concerning whether these are in fact separate species, 

or varieties or subspecies of other species.

Field research is required for the large number of taxa assessed as Data 

Deficient to determine distribution, population numbers, threats facing these 

taxa and to resolve taxonomic uncertainties. This should be carried out as 

a matter of urgency and full Red List assessments undertaken as soon as 

possible, so threatened taxa are added to the list of priority taxa for conservation concern.

As there are overlaps in reported distribution of many Data Deficient taxa, this 

information can be used to plan field surveys to obtain increased information 

on multiple taxa at once, thereby increasing output without needing increased 

budget and effort.

As an insurance policy, all Data Deficient taxa should be considered under 

threat until sufficient information is available to fully assess their conservation 

status, or taxonomic uncertainty is resolved.

Known distribution information and additional known information is provided 

for Data Deficient taxa on pages 32 - 36.
The Red List of Betulaceae

9

of plant diversity and the need for its 

conservation to be incorporated into 

communication, education and public 

awareness programmes.

Integrated Conservation of Tree Species 

by Botanic Gardens: A Reference 

Manual provides a step-by-step guide 

to achieving best practice in integrated 

conservation and is a valuable resource 

for botanic gardens and the wider 

conservation community.

It is hoped that this Red List of Betulaceae is a useful reference for botanic 

gardens, in situ conservation organisations and other conservation stakeholders, such as policy makers and 

funding bodies who play an important 

role in deciding the future of these taxa. 

Although this global assessment has 

highlighted a great need for increased 

research for many Betulaceae taxa, the 

current information available has been 

enough to define current conservation 

and research priorities.

It is hoped that by providing up to date 

conservation assessments of this family 

that conservation action will increase for 

the most threatened Betulaceae taxa. It 

is also hoped that this report is a useful 

resource for generating further interest 

and further funding to carry out field 

research to address current knowledge 

gaps.

GardenSearch

BGCI’s GardenSearch database is the only global source of information 

on the world’s botanical institutions. GardenSearch allows users to search 

over 3,000 profiles to locate botanic gardens, arboreta, zoos, and similar 

organization with specific resources and expertise. GardenSearch is a 

valuable tool for connecting researchers, collaborators, and the general 

public to botanical resources available in gardens worldwide. GardenSearch 

also provides a web presence for small institutions that do not have their 

own website, connecting them to the global conservation community. www.

bgci.org/garden_search.php

PlantSearch

BGCI’s PlantSearch database is the only global database of plants in 

cultivation, and is free to contribute to and access. PlantSearch connects 

around 2,000 researchers and horticulturists to collections every year. 

Locations and gardens are not publicly revealed, and requests can be made 

via blind email messages. PlantSearch is an easy way for ex situ collections 

to contribute to broader ex situ assessments such as this conifer survey. By 

uploading a taxa list to PlantSearch, collection holders can not only connect 

their collections to the global botanical community, but also find out the 

conservation value of their taxa including the number of locations each taxon 

is known globally and current global conservation status.

It is important for ex situ collections to share accurate data more broadly and 

keep it updated. PlantSearch relies on collection holders to upload up-todate taxa lists on an annual basis to ensure accuracy and enhance usability 

of the data. www.bgci.org/plant_search.php

Target 8 of the GSPC calls for 75% 

of threatened plant species in ex situ 

collections by 2020. Botanic gardens and 

arboreta play a valuable role in ex situ

conservation. While some threatened 

Betulaceae taxa are reported as held in 

well-managed ex situ collections, it is 

recommended that ex situ conservation 

efforts are increased for all taxa listed as 

threatened in this publication.

BGCI’s PlantSearch database is the only 

tool for measuring progress towards 

Target 8 of the GSPC at the global level. 

Following on from this report, BGCI will 

undertake a survey using data held in 

BGCI’s PlantSearch database to determine how well represented threatened 

Betulaceae taxa are in ex situ collections. 

This will help to further determine conservation priorities.

For ex situ collections to be of maximum 

value to conservation they should consist of material of wild origin and be 

genetically representative of wild populations. Collection management will also 

ideally involve propagation programmes 

to cultivate a supply of material for reintroduction and restoration programmes. 

Propagation programmes are extremely 

important for taxa that have high ornamental value and whose wild populations are subject to over-exploitation. 

Producing a supply of material for sale will 

reduce pressure on wild populations.

All conservation approaches will be 

of increased value if accompanied by 

awareness-raising and environmental 

education programmes, particularly 

aimed at communities living locally to 

threatened wild populations or reintroduction sites. The involvement of local 

people in conservation activities helps 

ensure the sustainability of efforts and 

ensure long term survival of these taxa 

in their natural habitats. This will also 

work towards achieving Target 14 of the 

GSPC which calls for the importance 
The Red List of Betulaceae

10

Taxonomic debate exists for this taxon. 

First described as a subspecies of B. 

lenta by Ashe it was later elevated to 

species level (B. uber) by M.L Fernald 

(U.S. Fish & Wildlife Service, 2005). 

In 2004, Ashburner and McAllister 

published an article stating it to be 

a forma of B. lenta based on genetic 

tests undertaken at Ness Botanic 

Gardens, University of Liverpool, UK. 

This report follows the taxonomy of the 

recent Betula monograph (Ashburner 

and McAllister, 2013) which treats 

this taxon as a forma of B. lenta. A 

separate conservation assessment is 

therefore not included in this report, 

however Betula lenta f. uber is still 

considered “well worthy of conservation” (Ashburner and McAllister, 2013) 

and is an example of a successful 

conservation plan.

Betula lenta f. uber is only found in 

Smyth County, Virginia U.S., on the 

banks of Cressy Creek. It was almost 

driven to extinction by habitat degradation from agriculture and logging activities, however thanks to a successful 

recovery plan most of its populations 

are now stable. After its initial discovery 

in 1918 by Ashe, the birch was not seen 

in the wild for almost 60 years. It was 

thought to be extinct until the rediscovery of 41 individuals by Ogle in 1975 

(U.S. Fish & Wildlife Service, 1994).

Subsequent wild searches of the 

surrounding area found no additional 

populations. It is now known that the 

only naturally occurring population 

grows within a narrow strip of highly 

disturbed, second growth forest along 

a 1,500 m stretch of floodplain in Cressy 

Creek. The population occurs on both 

private and public land and is almost 

entirely surrounded by agricultural land.

Within a few years of its re-discovery 

the population numbers decreased 

rapidly, by 1977 only 26 trees remained 

(U.S. Fish & Wildlife Service, 2005). In 

response a “Betula uber Protection, 

Management and Research Coordinating Committee” was formed. This 

committee was the driving force behind Betula uber becoming the first 

tree in the US to be given protected 

status under the U.S. Endangered 

Species Act (ESA). To prevent this 

species from disappearing again, 

fences were erected to reduce the 

threat of vandalism and theft and 

competing vegetation was cleared 

from potential seed sources. Thanks 

to these recovery efforts, the first and 

only documented case of natural reproduction occurred in 1981, producing 81 seedlings.

Seeds were also collected from mature 

individuals, germinated in greenhouses 

and kept in cultivation for a few growing seasons. In 1984, significant work 

began, involving the planting of greenhouse seedlings on U.S. Fish & Wildlife 

Service property, to increase numbers. 

Out-planting occurred at 20 plots 

within Cressy Creek drainage, with 

5 new populations established each 

year for 4 years. Each newly established population consisted of 96 

individuals and was monitored and 

managed by the USDA Forest Service.

In an important effort to increase ex 

situ collections as well as reduce theft, 

the US National Arboretum produced 

and distributed 50 seedlings to other 

arboreta, private nurseries and botanic 

gardens. By 1994, 19 of the 20 populations were considered self-sufficient 

and Betula uber was down listed from 

endangered to threatened under the 

ESA. In 1991, populations peaked to 

1,400 individuals (U.S. Fish & Wildlife 

Service, 1994).

Although the single natural population 

is still declining (only eight mature individuals remain), as of 2003 there are 

nearly 1,000 cultivated trees in botanic 

gardens and the wild thanks to the 

work of the protection committee, including the U.S. Fish & Wild Service, 

USDA Forest Service and individual 

researchers (U.S. Fish & Wildlife 

Service, 2005).

The lack of natural regeneration and 

only one true natural population means 

that Betula uber still listed as threatened in the U.S. under the ESA. Full 

recovery for this taxon now relies on 

successful natural reproduction and 

survival of the 20 cultivated populations growing in Cressy Creek.

Case Study 1: A successful Conservation Project, Betula lenta f. uber.
The Red List of Betulaceae

11

Stone Lane Gardens is a small 

woodland garden tucked away in a 

corner of Dartmoor National Park, in 

Devon, England. Stone Lane Gardens 

holds the UK National Collections of 

birch (Betula) and alder (Alnus) trees. 

Most specimens are wild collected.

The garden began life in the early 

1970s when Kenneth Ashburner 

began planting the Birch and alder 

he was collecting. Ashburner was 

considered one of the leading experts 

in Betula and his garden was also 

a place of study. Ashburner died in 

2010 with his great work to produce 

a monograph of the genus Betula, 

un-finished. Fortunately his co-author 

and great friend Dr. Hugh McAllister 

battled on with the book and thanks 

to his efforts ‘The genus Betula: A 

taxonomic revision of birches’ was 

published in 2013 (Ashburner and 

McAllister, 2013).

Stone Lane Gardens is now a charity, 

the role of which is to conserve the 

existing National Collections and 

maintain the garden for the enjoyment 

and education of the public, as well 

as adding new trees to the collections 

and continuing research of birch and 

alder taxa.

The National Collection of Birch includes several species that are rarely 

seen ex situ. For example, Betula 

delavayi is a small shrub from China 

that can struggle with the UK climate. 

Betula chichibuensis is a Japanese 

multi-stemmed small shrubby tree 

to 6 m that is considered Critically 

Endangered. Betula lenta forma uber

(Box 2) is a localised mutation from 

Virginia. Stone Lane Gardens has 

several provenances of the multistemmed shrub Betula ashburneri, 

which was first recognised as distinct 

in 1997.

Betula megrelica is a very rare and 

understudied species growing in isolation in north west Georgia. In 2013, 

the Rufford Foundation supported 

the Garden Manager of Stone Lane 

Gardens, Paul Bartlett, to undertake 

a conservation project in north west 

Georgia, which generated the information for the conservation assessment 

of B. megrelica presented in this 

publication.

Probably the most important feature 

of Stone Lane Gardens’ collections 

lies in knowing the provenance of 

their trees. This is of great value to 

botanists and scientists, who need 

non-hybridised genetic material (mostly 

wild-collected) to study. Stone Lane 

Gardens has supplied living material 

from Betula taxa to the British Museum 

for a study of birch tars. The gardens 

currently provide living birch material 

to the Biological Sciences department 

of Queen Mary University of London 

for a variety of molecular studies led 

by Dr. Richard Buggs.

Contributed by Paul Bartlett, Stone Lane 

Gardens, Devon. www.stonelanegardens.

com

Case Study 2: Stone Lane Gardens: The UK National Collection of Betula and Alnus

Betula ermanii growing at Stone Lane Gardens, UK. Least Concern (Pollet, C.)
The Red List of Betulaceae

12

The Bronze Birch Borer (Agrilus anxius) 

is a serious pest of Birch trees. This 

wood-boring beetle is native to North 

America, more common in warmer 

parts but present in small numbers as 

far north as Alaska. The adults are 

slender, metallic beetles, greenishbronze in colour and about 10 mm in 

length (Williamson and Pellitteri, 2003). 

The females lay their eggs in cracks 

and crevices in the bark of Birch trees 

and within a week the white, segmented 

grubs emerge and chew through the 

bark. Eventually the larvae disrupt the 

phloem tissue, reducing the amount 

of food transported from the leaves to 

the roots. The damaged root system 

cannot supply the leaves with enough 

water and the leaves in the upper canopy turn yellow and become sparse. 

This may lead to branch dieback, which 

further reduces the ability of the tree 

to produce food and will likely result 

in tree death. The mature larvae overwinter in the bark before emerging as 

adults the following spring. The exit 

holes of the adult beetle are a distinctive D shape (Williamson and Pellitteri, 

2003).

Bronze Birch Borers are known to attack 

all species of birch, however some 

species are more susceptible than 

others. Betula nigra, native to North 

America, is the most resistant species, 

but other American birches are less 

resistant: B. papyrifera, B. populifolia, 

B. lenta and B. alleghaniensis are

commonly attacked. The European 

and Asian birches, especially B. pendula and B. utilis, have little resistance 

and are effectively impossible to grow 

in the US (Wawryznski et al, 2009).

Bronze Birch Borers are not capable 

of successfully attacking healthy trees. 

They primarily attack birches that are 

weakened or stressed by drought, old 

age, insect defoliation, soil compaction, or injury. Healthy trees are able 

to produce callus tissue around the 

feeding gallery of the larvae which 

prevents further feeding (Katovich et 

al, 2003).

Management of this pest should therefore involve practices that promote 

healthy, vigorous birch tree growth. 

The ideal locations for birch trees are 

sites where the soil remains cool and 

moist and the trees receive full or partial 

sunlight on their leaves most of the day. 

Trees should be mulched and watered 

regularly, and injury to the tree should 

be avoided. Trees that have been infested should be cut down and destroyed before adults emerge in the 

spring (Katovich et al, 2003).

As the Bronze Birch Borer is a native 

insect to North America is should be 

viewed as a normal component of the 

birch ecosystem in North America and 

one that can be managed if environmental conditions remain the same. 

However, changes in climate and the 

continued global trade of trees and 

timber mean that it is possible that 

this pest could be introduced to other 

parts of the world. Birch species found 

elsewhere in the world have no resistance to this pest, and without the 

natural predators and environmental 

conditions that keep the Bronze Birch 

Borer in check in its natural range it has 

the potential to cause devastating loss.

Living ex situ collections can provide 

a vital monitoring network for the 

effects and spread of pests and 

diseases. In 2013, the International 

Plant Sentinel Network was launched: 

a jointly led initiative by BGCI and 

the UK Department of Environment 

Food and Rural Affairs (DEFRA) 

working with botanic gardens and 

arboreta around the world to provide 

guidance on diagnosis, monitoring 

and surveying of plant pests and 

diseases. Find out more at: http://

www.bgci.org/ourwork/ipsn/

Case Study 3: An increasing threat to birch trees: The Bronze Birch Borer
The Red List of Betulaceae

13

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(2013) The Genus Betula: A Taxonomic 

Revision of Birches. Kew Publishing, 

Kew

Ashburner, K. & McAllister, H.A. (2004)

Plate 487. Betula lenta f. uber. Betulaceae. Curtis’s Botanical Magazine. 21: 

54–60

BGCI (2014) GardenSearch online database. Accessed: 2014, www.bgci.org/

garden_search.php

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plant_search.php

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(1998) Trochetiopsis ebenus. Curtis’s 

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Byers, D.L. & Waller, D.M. (1999) Do 

plant populations purge their genetic 

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mating history on inbreeding depression. Annual Review of Ecology and 

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Coates, D.J. (1992) Genetic consequences of a bottleneck and spatial 

genetic structure in the triggerplant 

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to global change: The last 145 million 

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eds. Genetics and conservation of rare 

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Jackson, D.B., Fuller R.J. & Campbell, S.T. (2004) Long-term population 

changes among breeding shorebirds in 

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Park, T.Y. (2007) Systematic aspects 

of foliar flavonoids in subsect. Carpinus

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U.S. Fish and Wildlife Service (2005)

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The Red List of Betulaceae

15

Globally Threatened Betulaceae Taxa

Alnus henryi C.K.Schneid.

Chinese Red List, for example, lists this 

species as Least Concern, but consultation with local experts has confirmed 

that this species is very rare.

Some references suggest this species 

is common within its range, but it is 

more likely that the commonly occurring 

Alnus is A. formosana. Recent surveys 

of the reported distribution area have 

not found this species and it is therefore 

flagged as Possibly Extinct. A lack of 

herbarium specimens and taxonomic 

uncertainty mean that this species was 

last recorded for certain in the wild in 

1916 when the type specimen was 

collected. If this species is still present 

in Taiwan remaining population size is 

estimated to be fewer than 50 mature 

individuals.

This species is reported as held in ex 

situ collections, although very rare in 

cultivation, but it is thought that reported collections are in fact A. formosana 

rather than A. henryi.

Flooding and typhoons are common in 

the distribution area and may present a 

threat to this species.

Alnus henryi is a deciduous tree that 

grows to 20 m, with yellowish green 

branchlets. Leaves are glabrous and 

ovate or elliptic in shape. The tree is 

dioecious: the male inflorescence is 

catkin-like and the female inflorescence 

is subsessile. It flowers in autumn and 

fruits in late autumn. Woody cones 

contain nutlets with papery wings. It is 

reported to be a pioneer species.

Refs: 11, 42, 74, 77, 91, 94, 99, 133, 

208

CR D (PE)

Province of China (Taiwan: Tanshui)

Taxonomic note: There is some debate 

over the acceptance of this species. 

Further studies may show that it is 

conspecific with Alnus formosana. The 

only major difference between the two 

species appears to be one of phenology: A. formosana flowers in spring, 

while A. henryi flowers in autumn. Until 

genetic analysis has been carried out, it 

should be considered threatened. It is 

treated as an ‘uncertain species’ in the 

Flora of Taiwan (2nd ed.).

This species is endemic to Taiwan, 

reported to only occur in the Tanshui 

region of the island.

There are conflicting reports in available 

literature about this species. The 
The Red List of Betulaceae

16

Alnus maritima (Marshall) Muhl. ex Nutt.

of the species. Despite its name, in all 

locations Seaside Alder only occurs in 

fresh water tidal and non-tidal systems.

The combined area of occupancy of 

the fragmented subspecies populations 

is estimated to be less than 500 km2

. 

A combination of threats impact upon 

the Alnus maritima complex, including 

climate change, grazing and low genetic 

diversity, which are projected to cause 

decline in area of occupancy, quality of 

habitat and number of subpopulations. 

Alnus maritima is a multi-stemmed 

large shrub or small tree, with smooth, 

light grey bark. It has simple elliptical 

leaves with a leathery texture and a 

singly serrated margin. This species 

has vivid yellow, floral catkins and 

brown cone-like fruits which release the 

water-dispersed seeds. This species 

is the only autumn blooming member 

of its genus native to North America, 

all others bloom in spring. This characteristic is shared with two old-world 

Alnus species: Alnus nitida and Alnus 

nepalensis. This means that the nearest 

extant relatives of Alnus maritima are in 

southern Asia. 

This species has a NatureServe ranking 

of Vulnerable. The reasons for this 

are its scattered range (small areas of 

Oklahoma, southwestern Delaware and 

adjacent eastern Maryland, and one 

areas in Georgia), with few sites overall. 

This species was listed as Rare in 

Delaware and Maryland, and Vulnerable 

in Oklahoma in the 1997 IUCN Red List 

of Threatened Plants and LR/nt in the 

World List of Threatened Trees in 1998.

Refs: 44, 63, 70, 74, 88, 103, 104, 129, 

133, 134, 143, 155, 162, 173, 183, 

184, 185, 201, 208, 222, 224, 236

EN B2ab(ii,iii,iv)

United States (S Delaware, NW 

Georgia, SE Maryland, SC Oklahoma)

Taxonomic note: There was some 

debate over the acceptance of the three 

subspecies, but recent genetic studies 

have concluded that there are three 

geographically disjunct subspecies of 

Alnus maritima.

Endemic to the United States, Alnus 

maritima (Seaside Alder) is a very 

disjunctly distributed tree species, with 

populations so widely separated that 

they are considered distinct subspecies. 

The distinct genetic identity of each 

subspecies, the reduced genetic diversity within each subspecies and the lack 

of gene flow among populations within 

each region mean that it is important to 

protect all populations to conserve the 

genetic diversity and long-term viability 

Alnus maritima
The Red List of Betulaceae

17

County, Delaware this taxon occurs on 

small ponds formed by the damming 

of small creeks. This taxon only occurs 

in open sunny areas, in shaded areas 

this subspecies is replaced with Alnus 

serrulata. 

Due to a lack of monitoring of this 

subspecies the extent of occurrence 

and area of occupancy is unknown. 

As a substitute the total km2

 of water 

area in the five counties where this 

subspecies occurs was calculated. 

There is 3,136.8 km2

 of water. Obviously 

the actual extent of occurrence is much 

less than this number, thus A. maritima

subsp. maritima meets criterion B1, extent of occurrence less than 5,000 km2

.

Although the population appears stable, 

climate change poses a significant 

threat to the population in the future. 

The Intergovernmental Panel on Climate 

Change (IPCC) is projecting significant 

increases in sea level by the end of 

the 21st century due to global warming 

causing expansion of global sea water 

and increased melting of glaciers and 

ice sheets. This rise in sea level will lead 

to salt water intrusion into current fresh 

water tidal systems and will lead to 

local extirpation of A. maritima subsp. 

maritima populations. 

There are currently no active conservation measures in place for this subspecies. The most practical conservation 

measure that should be implemented is 

ex situ conservation and seed collection 

from the whole range of the subspecies 

to preserve potential local adaptability 

and overall genetic diversity. 

This taxon has not yet been ranked 

(G3TNR) on NatureServe. 

Refs: 70, 88, 104, 133, 143, 183, 184, 

185, 201, 222

Alnus maritima subsp. maritima

EN B1ab(i,ii,iii,iv)

United States (Delaware, Maryland)

Alnus maritima subsp. maritima

populations are located in the Delmarva 

Peninsula in Delaware and Maryland. 

In Maryland (Dorchester, Somerset, 

Wicomico and Worcester Counties) 

and western Sussex County, Delaware, this subspecies is found in the 

upper reaches and tributaries of the 

Choptank, Nanticoke, Pocomoke and 

Wicomico rivers. In eastern Sussex 

Alnus maritima subsp. georgiensis J.A.Schrad. & W.R.Graves

United States (Georgia: Bartow County)

CR B1ab(i,ii,iii,iv,v)+B2ab(i,ii,iii,iv,v)

This subspecies, commonly known as 

Georgia Alder, is known only from the 

east end of Drummond Swamp in Bartow 

County, Georgia and has an extent of 

occurrence of 0.5–0.7 km2

 and occupies an area of only 0.14 km2

. It is a 

Alnus maritima subsp. georgiensis (Nourse, H & C)
The Red List of Betulaceae

18

shrub with many stems originating from 

the base and is found in open, standing 

water of a sag pond. The population 

here is currently stable but its location 

adjacent to agricultural lands where 

cattle are grazed is threatening this 

species. The runoff from these fields 

is decreasing the water quality leading 

to eutrophication. Climate change is 

also predicted to cause population 

decline or extirpation from this site. 

A lack of genetic diversity, lack of 

seedling recruitment and other potential 

stochastic events could also lead to 

population decline. 

Three experimental research populations have been established on 

protected land to study the ability to 

establish additional populations of this 

species. Ex situ collections have been 

established at the Atlanta Botanical 

The extent of occurrence is 9.8 km2

 and 

the area of occupancy is 2.97 km2

.

Although these two subpopulations 

appear stable at this point in time, a 

threat from climate change is inferred, 

along with decreasing volumes of water 

in the local aquifer. A lack of genetic 

diversity and no known recruitment from 

seed and/or stochasticity will lead to a 

decrease in population numbers with a 

concurring decrease in habitat quality. 

This taxon is therefore categorised as 

Critically Endangered. 

In situ conservation is being pursued 

to protect populations on both the 

Blue River and Pennington Creek and 

a graduate student is currently conducting research on the establishment 

of this species on an island in the Blue 

River to determine if out-planting is a 

viable conservation action. 

This taxon has not yet been ranked 

(G3TNR) on NatureServe (ref 143). 

Refs: 70, 104, 133, 143, 173, 183, 184, 

185, 222

Assessor: Stritch, L.

Alnus maritima subsp. oklahomensis J.A. Schrad. & W.R. Graves

CR B1ab(i,ii,iii,iv,v)+B2ab(i,ii,iii,iv,v)

United States (Oklahoma)

Alnus maritima subsp. olkahomensis

(Oklahoma Alder) is the most distinct 

of the three subspecies, with narrower 

leaves and larger trunks and canopies. 

This subspecies is known from only one 

population with two subpopulations; 

one occurring along Pennington Creek 

in Johnston County and the other 

along the Blue River in Johnston and 

Pontotoc Counties. In both locations 

this subspecies occurs in shallow water 

at the edges of the river in open sunny 

areas between 208 m and 215 m ASL. 

Garden and the State Botanical Garden 

of Georgia. Ex situ seed collections 

have also been made. 

This taxon is ranked G3T1 (Critically 

imperiled) on NatureServe (ref 143).

Refs: 63, 103, 104, 129, 133, 134, 143, 

162, 183, 184, 222

Alnus maritima subsp. georgiensis (Nourse, H & C)
The Red List of Betulaceae

19

Since precise population reduction 

data is not available this is a preliminary 

assessment and does not alter the 

2005 assessment. Further population 

information is needed to make a full 

assessment. 

Loss of forest cover in the distributional 

area of this species is reported to lead 

to increased waterlogging in the bottom 

of valleys, where this species often 

occurs. However, it is reported that 

this species might be one of few native 

tree species that can persist in these 

new environmental conditions and 

outcompete the exotics. As a result, 

active afforestation using A. subcordata

is being considered as an option to 

restore the new waterlogged degraded 

areas in the forest. 

Alnus subcordata is a fast growing 

species, growing to 25 m tall. It is 

found in mixed damp woodland, or as 

a pioneer species following floods or 

land-slides. 

Refs: 15, 74, 133, 136, 208, 256

Assessor: IUCN/SSC Caucasus Plant 

Red List Authority

Alnus subcordata C.A.Mey.

VU A2c

Azerbaijan, Islamic Republic of Iran

This species has a small distribution. 

This species was evaluated as VU A2c 

in a provisional assessment undertaken 

during a tree Red Listing workshop held 

in Tbilisi, Georgia, 26–28 September 

2005, due to a reported population size 

reduction of at least 30% over the last 

three generations and an extent of 

occurrence of less than 35,000 km2

. 

Part of the range of this species, in 

the Hyrcanian forest of Iran, is subject 

to deforestation for agriculture, road 

construction, overgrazing and fires. The 

decline in area of occupancy, extent of 

occurrence and/or quality of habitat is 

therefore predicted to be continuing. 

NT

China (Xizang)

Taxonomic note: B. delavayi, B. bomiensis, B. calcicola and B. potaninii taxa are 

sometimes confused. However they are 

separable by their visible morphological 

characters, ploidy and geographical 

distribution.

A small tree to 8 m, this species grows 

in the margins of broad-leaved forests 

or dry scrub. B. bomiensis is reported 

to be a little known species. It is known 

only from the type and three other collections and a small number of cultivated 

specimens exist as a result of these 

collections.

The data points available for this 

species give an extent of occurrence 

Betula bomiensis P.C.Li
The Red List of Betulaceae

20

greater than the threshold for it to be 

considered Vulnerable, but the area the 

species occupies within this range is 

likely very small (<2,000 km2

), as inferred 

from a low number of reported sightings 

or collected specimens. It is therefore 

assessed as Near Threatened.

This species may qualify for a higher 

threat category under criterion B due to 

the fragmented nature of the population 

(again inferred from limited collections 

or reported sightings within its range) 

and projected continuing decline in 

area, extent and quality of habitat as a 

result of deforestation which is a high 

threat in Tibet (B2ab(iii)).

This species is not assessed on the 

Chinese Red List. Further field research 

is required to verify if this species 

qualifies in a higher threat category.

This species has been cultivated at 

Liverpool University Botanic Gardens, 

UK. It is self-incompatible, therefore 

successful establishment in cultivation 

will depend on the maintenance of 

at least one breeding population to 

provide viable seed for distribution. 

Cuttings taken from seedlings root 

easily and viable seed which comes 

true is produced where the different 

clones are grown together. This species 

would benefit from increased conservation action through in situ and ex situ 

conservation.

Refs: 5, 74, 77, 99, 133, 208

Range in Yunnan. A shrub generally 

1–2 m tall, this species forms thickets 

on damp limestone rocks and cliffs. 

Possible threats include habitat fragmentation and deforestation due to 

rapid development in Yunnan; however 

the Lijiang Shan is reported to be one 

of the best preserved areas of China.

The data points available for this species 

give an extent of occurrence within the 

threshold for this species to be considered Vulnerable (under criterion B1b(iii). 

However, there are limited data points 

available and the extent of occurrence 

could be higher than represented by 

the available data points. The full range 

of this species is still estimated to be 

small and potential threats have been 

identified. It is therefore assessed as 

Near Threatened. Further field research 

is required to verify if this species 

qualifies in a higher threat category.

This species is not assessed on the 

Chinese Red List.

Refs: 5, 42, 74, 75, 99, 133, 207, 208

Betula calcicola (W.W.Sm.) P.C.Li

NT

China (SW Sichuan?,* NW Yunnan)

Taxonomic note: B. delavayi, B. 

bomiensis, B. calcicola and B. 

potaninii taxa are sometimes confused. 

However they are separable by their 

visible morphological characters, ploidy 

and geographical distribution.

This species is only known for certain 

only from Yulong Shan, in the Lijiang 

* If occurrence in a location is uncertain, the location is followed by a question mark (?).
The Red List of Betulaceae

21

to be fairly tolerant of wet soils and is 

relatively drought tolerant, at least once 

established.

The small population and restricted 

distribution of B. chichibuensis make 

it susceptible to natural disaster or 

disease. The species is also self-incompatible, requiring two individuals 

to be close enough to cross-pollinate 

one another, making seed production 

uncertain in small populations. Wild 

collected seed has also shown very low 

viability (less than 1%).

However, when several clones are 

grown close together in cultivation seed 

viability is high. In 1986, seeds were 

collected from trees growing on Mount 

Kamo-san and sent to Ness Botanic 

Gardens, University of Liverpool, UK. 

Eight clones from the original seeds 

are now in cultivation, and have been 

distributed to arboreta and botanic 

gardens in Europe and North America. 

Seedlings from the original wild-collected seeds showed considerable 

variability in habit characteristics and 

most have flowered and fruited freely. 

As this species is easily propagated by 

cuttings, it is possible for commercial 

reproduction to occur from a single 

plant, and for one, self-incompatible 

clone to dominate the cultivated market 

of this species in the future. Care should 

be taken to maintain genetic diversity of 

this species.

Betula chichibuensis grows as a 

multi-stemmed shrub or small tree up 

to 10 m in height. Its bark is brown and 

its leaves are soft, green and ovate in 

shape. This species is monoecious with 

creamy yellow male catkins and red 

female catkins with tufts of violet styles. 

Flowering occurs May to June. The 

fruiting catkins are short, upright and 

contain wingless seeds.

This species is assessed as Endangered in the Red List of Threatened 

Plants of Japan . This species was 

assessed as Rare in the 1997 IUCN

Red List of Threatened Plants.

Refs: 5, 11, 74, 77, 132, 133, 141, 208, 

236, 259

Betula chichibuensis H.Hara

CR B1ab(iii)+B2ab(iii); D

Japan (Honshu: Chichibu)

Endemic to Japan, this species occurs 

only on the island of Honshu. It has 

a very small extent of occurrence, 

confined to the Chichibu area in the 

mountains of Central Honshu on Mount 

Kamo-san, near Tano-Gun, in Gunma 

Prefecture. It occurs as subpopulations 

and the area of occupancy is estimated 

to be very low (<10 km2

). The population 

was reported to have reduced to just 

21 remaining individuals in the wild in 

1993. This species has no close living 

relatives anywhere else in the world, is 

considered a relict species and is likely 

to be of very ancient origin. Deforestation 

and habitat degradation are also evident 

in the Chichibu District, presenting a 

threat to the survival of this species. This 

species is reported to be a conservation 

priority by Ashburner and McAllister.

This species grows in limestone 

outcrops. Although young immature 

plants appear to be relatively shade 

tolerant, mature trees are very intolerant 

of shade. The species also appears 

Betula chichibuensis
The Red List of Betulaceae

22

Its existence as small populations also 

makes these populations susceptible to 

human activities, such as land clearance. 

Future decline in area of occupancy, and 

loss of subpopulations, are therefore 

projected Field research is required to 

verify the current distribution of this species, and determine if it should already 

be placed within a threat category.

This species is very rare in cultivation. It 

is self compatible and can be propagated easily by seed, although seedlings 

are susceptible to slugs and drought.

B. globispica is a very distinct relict species from Honshu with no close living 

relatives anywhere else in the world. 

A tree to 21 m it is found on steep 

mountain slopes and rocky outcrops. It 

prefers very heavy clay which, although 

wet, does not become waterlogged.

This species was assessed as Rare in 

the 1997 IUCN Red List of Threatened 

Plants. This species is reported to be 

a conservation priority by Ashburner 

and McAllister. It is assessed here as 

Near Threatened, almost qualifying as 

Vulnerable under criterion B2ab(ii,iv).

Refs: 5, 74, 133, 154, 208, 222, 236

CR D (PE)

China (NW Yunnan: Gongshan Drungzu 

Nuzu Zizhixian)

Endemic to China, this is an apparently 

distinct species known only from a single 

specimen in the herbarium in Kunming. 

The specimen was collected from 

2,600 m ASL in the mixed, broadleaved 

forests of Drungzu Nusu Zizhixian near 

Gongshan, east of Lijiang in northwest 

Yunnan. This species is assessed as 

Critically Endangered on the Chinese 

Red List. This species is assessed as 

Critically Endangered here due to a 

very small population size, likely to be 

less than 50 mature individuals left in 

the wild, and is flagged as possibly 

extinct as there is no record of the 

species since the type specimen was 

Betula globispica Shirai

Betula gynoterminalis Y.C. Hsu & C.J. Wang

NT

Japan (C and SC Honshu)

The species is endemic to Japan and 

is only found in the Chubu (central) and 

Kantö (eastern) districts of the island of 

Honshu. The total distribution area of 

the two regions where this species is 

reported to be found is c.110,000 km2

.

Much of this area is mountainous, which 

is the habitat type that this species 

prefers, however, it is reported to be 

rare within its range and to exist as small 

subpopulations. The area of occupancy 

is therefore estimated to be approaching 

the threshold value for qualifying as Vulnerable (i.e. nearly 2,000 km2

). Presence 

on mountain areas means these subpopulations may be genetically isolated.

This species is susceptible to drought, 

even as a relatively well-established tree. 
The Red List of Betulaceae

23

collected in 1956. Field studies are 

required to determine if this species still 

exists in the wild and if so, to determine 

population size and whether it is found 

in other localities. There is no record of 

field surveys having found this species 

since the initial type specimen was 

collected. 

The forests of northwest Yunnan are 

under threat from increased timber 

collection for fuelwood and building 

supplies, and loss of habitat due to 

increasing development. If populations 

do remain, it is likely they are under 

increasing threat. If populations of this 

species are located, both in situ and ex 

situ conservation actions should be 

taken. 

Betula gynoterminalis appears to have 

a unique morphology, probably most 

closely related to B. delavayi and B. calcicola. It is a small tree to 7 m with dark 

purple branches. The large ovate leaves 

are very hairy on the underside with 

prominent veins and serrated margins. 

The nutlets have very narrow wings and 

the fruiting catkins are pendulous and 

borne terminally, which is unusual for 

a birch. This species flowers between 

June and July and fruits between July 

and August.

Refs: 5, 42, 74, 99, 133

Betula medwediewii Regel

NT

Georgia, Turkey-in-Asia, Islamic Republic of Iran?, Azerbaijan?, Armenia?

A relict species confined to the Caucasus 

Mountains, Betula medwediewii is distributed in the western Transcaucasus 

and the adjacent mountains of northeastern Turkey. This species is found 

growing in Adjara in south-western Georgia, on Mount Jvari in western Georgia 

and in the provinces of Rize and Artvin 

(formally Çoruh Vilayet) in north-eastern 

Turkey. This species is reported as rare 

across its range, especially in Georgia 

where populations are very small, fragmented and unstable. Presence in Iran, 

Azerbaijan and Armenia has not been 

confirmed. 

This species is found on sub-alpine 

mixed forests and open hillsides at 

elevations between 600–2,400 m ASL. 

This species is heavily over-grazed from 

wild and domestic animals. Grazing 

causes damage to both the trees and 

seeds, and has the risk of reducing 

natural reproduction. Poor forest management and uncontrolled logging are 

also major problems in the regions 

where this tree is found. 

This species is deep rooted and drought 

tolerant, but has very specific growing 

requirements. It is not shade tolerant and 

struggles to compete with fast growing 

trees or shrubs as it is slow growing. 

This species prefers a limestone based 

soil. This limits its range to cleared 

ground above the tree-line where there 

is little competition and the right soil. 

Betula medwediewii on Mt Tbeti in Adjara, Georgia. Near Threatened (Bartlett, P., Stone Lane Gardens)
The Red List of Betulaceae

24

However, it cannot survive too high 

because of the harsh winter climate at 

high altitudes within its range.

Betula medwediewii nearly meets the 

threshold for qualifying as Vulnerable 

under criterion B1ab. This species was 

evaluated as Vulnerable under criterion 

B1ab(iii,v) in the Red List of the Endemic 

Plants of the Caucasus, based on a 

provisional assessment undertaken 

during a Global Tree Specialist Group 

workshop in Tbilisi in 2005. The updated 

assessment evaluating this species 

as Near Threatened is based on more 

recent distribution information and has 

been verified by members of the IUCN/

SSC Caucasus Plant Red List Authority. 

Betula medwediewii is occasionally 

grown in arboreta and a few large 

gardens in Europe. Seed has been obtained from Çoruh and Borçka Districts 

in Turkey and from Mt Migaria region in 

the Caucasus. As yet no propagation or 

reintroduction programs have been set 

up for this species. 

This multi-stemmed spreading shrub 

grows up to 5 m tall. It has metallic, 

reflective bark with conspicuous 

lenticels and large ovate to circular, 

deeply veined, dark green leaves. Male 

flowers are catkin-like and very long, 

female flowers are inconspicuous. 

Fruiting catkins are yellow, large, upright 

and persistent with brown scales. 

Refs: 5, 9, 11, 30, 52, 54, 74, 110, 133, 

192, 208, 222, 255

Betula megrelica Sosn.

region of the Caucasus mountain range. 

This species is rare across its range. 

It was previously known from one specimen taken from Mt Migaria in 1934 by 

D.Sosnovsky. In 2013, two populations 

were located on Mount Migaria and 

Mount Jvari in the Mingrelia region. The 

population on Mount Jvari was estimated 

to spread for 3 km along the north face 

of the ridge, covering an area of 3.0 km x 

0.5 km. The population on Mount Migaria is estimated to spread over a potential 

area of 2.0 km x 0.5 km. Estimates suggest there may be up to 8 fragmented 

subpopulations and suitable habitat in 

nearby areas has been identified. These 

new potential subpopulations would 

increase the extent of occurrence, area 

of occupancy and total population, but 

all are estimated to remain low (EOO 

< 5,000 km2

, AOO < 500 km2). If no 

other subpopulations are identified this 

species would qualify as Critically Endangered. Further field study is needed 

to verify distribution and population size. 

There is an observed continuing decline 

in the area, extent and quality of habitat 

and number of mature individuals, as 

a result of wood extraction for fuel and 

grazing. The main threat to this species 

is overgrazing from livestock and wild 

animals, which causes damage to the 

trunk and stems. Shrubs growing at 

lower elevations are more at risk from 

overgrazing. Other threats include poor 

forest management and uncontrolled 

logging. Although this species is located 

within the Samegrelo Planned Protected 

EN B1ab(i,ii,iii,v)+2ab(i,ii,iii,v)

W Georgia (Mt. Migaria, Mt. Jvari)

Betula megrelica is a relict species 

endemic to Georgia, found only on two 

mountains in the Mingrelia (Samegrelo) 

Betula megrelica growing on Mt Jvari, 

Georgia. Endangered (Bartlett, P., Stone Lane 

Gardens)

Betula megrelica growing on Mt Migaria, 

Georgia. Endangered (Bartlett, P., Stone Lane 

Gardens)
The Red List of Betulaceae

25

Area, there seems at present little to 

no control on the use or misuse of the 

resources on the ground. This species 

has very specific habitat requirements. 

The habitat must be high enough to 

suppress the growth of taller species, 

steep enough to avoid damage from 

grazing livestock, the aspect is between 

north and east, and on limestone. 

This species is fairly rare in cultivation, 

reported to only occur in the University 

of Liverpool Botanic Gardens, Wakehurst Place and Stone Lane Gardens, 

all of which are in the UK. There are no 

known propagation or reintroduction 

programmes set up for this species 

at present, however recent research 

in Georgia has been essential in 

improving the understanding of this rare 

species. Identifying that B. megrelica

has a restricted, niche habitat makes it 

susceptible to damage and destruction 

by both man-made and natural events. 

Future conservation work aims to 

propagate seedlings collected from the 

Mingrelia region for possible use in a 

reintroduction programme and further 

explore the region for more populations. 

Betula megrelica is a small shrub, 

1–4 m in height, with several main 

stems radiating from just above soil 

level. These stems are often horizontal 

or even downward curving. It has a 

similar appearance to B. medwediewii

but has much smaller, narrower leaves 

and smaller fruiting catkins. At high 

elevations it forms dense thickets and 

dwarf forests on grassy slopes. It can 

also be found growing from the sides 

of rock outcrops with little soil. At lower 

elevations the shrub grows smaller and 

sparser. It is likely that the shrubs are 

covered by snow throughout the winter 

season. 

This species was listed as Indeterminate in the 1997 IUCN Red List of 

Threatened Plants. This species was 

evaluated as Vulnerable under criteria 

B1ab(iii,v)+2b(iii,v) in the Red List of the 

Endemic Plants of the Caucasus, based 

on a provisional assessment undertaken 

during a Global Tree Specialist Group 

workshop in Tbilisi in 2005. The higher 

threat category suggested here is 

based on data gathered from more 

recent surveys, indicating that the actual 

extent of occurrence and area of occupancy of this species is more restricted 

than previous estimates suggested. 

Refs: 5, 7, 9, 11, 74, 110, 126, 133, 

208, 222, 236, 255

Betula murrayana B.V.Barnes & Dancik

CR D

Taxonomic note: Some debate exists 

over whether this species should be 

considered an independent taxonomic 

lineage

Canada (Ontario), United States 

(Michigan)

Described as a new species in 1985, 

this species is an unusual natural 

hybrid of an already naturally hybridised 

species, Betula x purpusii, crossed 

with another native species, Betula 

alleghaniensis. 

B. murrayana has a severely fragmented population, containing two 

subpopulations separated by a distance 

of approximately 320 km. 

Betula megrelica growing on Mt Migaria, Georgia. Endangered (Bartlett, P., Stone Lane Gardens)
The Red List of Betulaceae

26

The site from which this species was 

first collected was from a low swampy 

area adjacent to a lake in Washtenaw 

County, Michigan. Two individuals 

were found here in the early 1980s, 

but one individual has since died. 

A high likelihood that the second 

individual may die before new seedlings 

become established is inferred, which 

would lead to a loss of one of the two 

subpopulations. 

In 1987, a second occurrence was 

discovered in Norfolk County, Ontario. 

This likely represents an independent 

origin of the species. Although no hard 

population data exists for the Ontario 

subpopulation, it has been inferred 

that there are less than 25 individuals 

and more than likely, based on the 

Michigan subpopulation data, less than 

10 individuals. This species therefore 

qualifies as Critically Endangered under 

criterion D. 

At both sites B. murrayana faces threats 

from stochastic events and small 

population size. 

The species nearly qualifies as Critically 

Endangered under criterion B, as the 

two subpopulations have an extent 

of occurrence and area of occupancy 

of less than 1.0 km2

, but it has been 

suggested that it is highly likely that this 

species will be found elsewhere in the 

Great Lakes/St Lawrence Valley areas 

as it is a hybrid, but it is not thought 

additional subpopulations would be 

large enough to reduce the proposed 

category.

Ex situ collections of B. murrayana are 

held in the Holden Arboretum, the University of Michigan Matthaei Botanical 

Gardens (US) and the Ness Botanic 

Garden, University of Liverpool (UK). 

The specimen in the Holden Arboretum 

has recently been diagnosed with 

Bronze Birch Borer (see Case Study 3). 

However, the single tree in cultivation 

at the Ness Botanic Garden produces 

viable seed which comes true. These 

seedlings are now being distributed to 

other botanic gardens to increase the 

security of ex situ collections.

This naturally occurring hybrid takes 

different characteristics from its related 

taxa. The bark is shiny, smooth, dark 

red with pale horizontal lenticels and 

peels in a similar way to B. allegheniensis. The leaves are ovate with serrated 

margins similar to Betula x purpusii but 

are larger. This is a medium sized tree 

to 15 m tall, usually with several trunks. 

It flowers in late spring and fruits in late 

autumn.

This species is ranked G1Q (Critically 

imperilled with questionable taxonomy) 

on NatureServe. This species was listed 

as Endangered in the 1997 IUCN Red 

List of Threatened Plants. 

Refs: 5, 6, 44, 133, 143, 221, 222, 224, 

236

Assessor: Stritch, L. Betula murrayana (Reznicek, A.A., michiganflora.net) Betula murrayana (Reznicek, A.A., michiganflora.net)
The Red List of Betulaceae

27

CR B1ab(iii,v)

Province of China (East Taiwan: Hualien 

Xian)

Endemic to Taiwan, this species is known 

only from the type specimen locality in 

Batakan, Hualien Xian (Hualien County). 

Within this locality, the species has 

small and fragmented subpopulations, 

distributed 20 km along the Li-Wu 

riverbank.

It is assessed here as Critically Endangered due to its limited extent of occurrence, being only known from only a 

single location and a projected decline 

in number of mature individuals and 

quality of habitat as a result of natural 

threats.

Betula tianschanica Rupr. 

reported as a threat (to its synonym B. 

jarmolenkoana). Part of the range of this 

species is within a protected area; the 

Xinjiang Tian Shan mountain system 

in China, a World Heritage Site. It is 

therefore better conserved within this 

part of its range, but no other reported 

conservation actions are in place in 

other parts of its range. 

This species was assessed as Endangered A2ac; B2ab(ii,iii) on the IUCN

Red List (in 2007) and in the Red List of 

Trees of Central Asia (in 2009). These 

assessments did not take occurrence in 

Mongolia into account and presence in 

Tajikistan was uncertain. These occurrences increase the area of occupancy 

of this species, likely above threatened 

thresholds. Population information in 

these new areas is not available and 

therefore it cannot be assessed under 

criterion A over its entire range. 

This species is assessed as Near 

Threatened under criterion A, assuming 

the known decline in population in parts 

of its range equates to a total population reduction of nearly 30%. 

Refs: 5, 39, 42, 74, 77, 99, 100, 133, 

208, 220, 222, 246

Carpinus hebestroma Yamam.

NT

China (Xinjiang: Tian Shan), Kazakhstan, 

Kyrgyzstan, Mongolia, Tajikistan, 

Uzbekistan

This species occurs in the river basins 

and valleys of western Tian Shan 

(Ugan, Pskem and Chatkal). It is found 

from 1,300 to 2,500 m ASL in Xinjiang 

(China). Despite a fairly wide range, 

this species has a restricted area of 

occupancy. Populations are fragmented. Populations in Central Asia (Uzbekistan, Kazakhstan and Kyrgyzstan) 

have declined at a rapid rate (exceeding 

50% over the past 3 generations). 

This species is threatened by livestock 

grazing, wood collection, avalanches 

and tourism in Central Asia, but these 

threats are likely present across the 

range of this species. Fire has also been 
The Red List of Betulaceae

28

Carpinus putoensis W.C.Cheng

sexually in the wild, but strong winds 

during flowering and seed-setting 

stages mean natural regeneration is 

almost absent. Low soil fertility also 

hinders natural succession and many 

once forested areas are now covered 

by tussock rangelands and grasses. 

Carpinus putoensis is cultivated in the 

Hangzhou Botanical Garden where 

various propagation experiments are 

being conducted. This species is also 

part of a conservation programme led 

by the Zhoushan Institute of Forestry. 

This has involved cultivation and 

planting of approximately 79 individuals 

in a 1 hectare near situ reintroduction 

site, close to the remaining single 

mature individual. These 79 individuals 

were planted 30 years ago, but have 

not yet reached maturity. 

A joint BGCI and Zhoushan Institute of 

Forestry initiative is also propagating 

a supply of plants to be planted 

on Huaniao Island, next to Putuo 

Island, establishing an additional near 

situ reintroduction site providing further 

protection for the species, and enabling 

reintroduction to Putuo Island in future. 

Full floristic survey of Huaniao Island is 

also underway. If C. putoensis is found 

on Huaniao Island in situ conservation 

measures will be put in place. 

Conservation measures being undertaken for this species will help improve 

the chance of survival. C. putoensis is 

a deciduous tree, up to 13 m tall. It has 

brown grey bark and elliptic leaves with 

double serrated margins. 

Refs: 11, 42, 74, 99, 105, 121, 123, 

133, 171, 190, 208, 241, 253

CR D

China (Zhejiang: Zhoushan Dao)

Carpinus putoensis is endemic to Putuo 

Island of the Zhoushan Archipelago, 

Zhejiang Province, China. Originally 

growing in evergreen broad-leaved 

forests, this species now exists as a 

single mature individual (approximately 

200 years old), preserved on the top of 

Foding Mountain. This species might 

have disappeared many years ago if 

it was not for its location beside Huiji 

temple, an indirectly protected environment. This single tree was discovered in 

the early 1930s and since then no more 

wild individuals have been found. 

The islands of the Zhoushan Archipelago have unique geographical 

environments and climatic conditions 

and their forests have been subjected 

to intense human use for many years. 

It is for these reasons that there are 

many rare and endangered tree species 

endemic to these islands. A new 

marine economy zone in the Zhoushan 

Archipelago is increasing human activity 

in this area, further threatening these 

rare species. 

Putuo Island has been proclaimed a 

nation’s key nature reserve and this 

species is under first-grade state 

protection. A fence has been erected 

around the remaining C. putoensis tree 

to protect it with an interpretation panel 

containing information about the tree. 

With a well-developed root system, 

this species is thought to be able to 

withstand both drought and storms. 

The species is monoecious, thereby 

in principle is still able to reproduce 

This species is threatened by 

disturbances including landslides 

after typhoons, which are common in 

Taiwan. The habitat of this species is 

located in the Taroko National Park 

which is a protected area, but this does 

not provide protection against natural 

occurrences.

This species is very rare in cultivation 

and is not currently known to be 

involved in any propagation or reintroduction programmes. This species 

would benefit from ex situ conservation 

to provide additional protection against 

natural threats.

Carpinus hebestroma is a small deciduous tree to 8 m, with greyish black 

bark and lanceolate shaped leaves with 

serrated margins. The tree is monoecious and flowers between May–July. 

It prefers to grow on limestone areas 

in montane forests, and is found at an 

altitude of 1,000–1,500 m ASL.

Refs: 11, 42, 74, 91, 94, 99, 120, 133, 

208
The Red List of Betulaceae

29

Carpinus tientaiensis W.C.Cheng

CR B1ab(iii)+2ab(iii); C2a(i); D

China (Zhejiang: Tianmu Shan)

Endemic to China, this species is only 

found in the forests of Tiantai Mountain 

in the North West Province of Zhejiang. 

It has a reported area of occupancy of 

0.03 km2

. This species is rare and it is 

reported that only 21 mature individuals 

exist in the wild, at a single location. 

Decline in area, extent and quality of 

habitat is observed and predicted to 

continue. Observed population decline 

is due to deforestation and conversion 

of land into monoculture plantations of 

bamboo and tea. A very small population makes this species susceptible to 

stochastic events as well as continued 

habitat loss. Competition from other 

species is also a threat, especially 

bamboo which is a fast growing species 

reaching full size within 3–4 months. 

Conservation of this species should be 

a priority. 

This species is not known to cultivation. 

No propagation or reintroduction programmes are known to exist for this 

species. 

Carpinus tientaiensis is a medium sized 

tree, reaching heights of 16–20 m. It is 

found growing in forests on mountain 

slopes. 

Carpinus tientaiensis is assessed as 

Critically Endangered, occurring in a 

single location with a very small area of 

occupancy and extent of occurrence, 

with a low population number. Decline 

in area, extent and quality of habitat is 

also observed and predicted to continue.

This species is also assessed as Critically 

Endangered on the Chinese Red List.

Refs: 11, 42, 74, 99, 105, 133, 171, 

208

Corylus colchica Albov

VU B1ab(iii)+B2ab(iii)

Georgia

This species is endemic to Georgia, 

found in Abkhazeti (Bzipi range, Mt. 

Arabika massif, Kodori range) and 

Samegrelo (Egrisi range).

The extent of occurrence of this species 

is estimated to be 5,000–20,000 km2

and the area of occupancy is estimated 

to be 500–2,000 km2

.

The population of this species is severely 

fragmented and composed of 15–20 

small subpopulations, occurring in rocky 

limestone areas from the middle montane through to subalpine zones. This 

species is threatened by forest clear 

cutting and grazing. Forest clearance 

is ongoing across Georgia and there is 
The Red List of Betulaceae

30

Ostrya chisosensis Correll

of oak (Quercus) pine (Pinus) woodlands 

along streams and on adjacent moist 

slopes. As such, these two taxa are to 

be considered glacial relicts restricted to 

these canyons as well as reproductively 

isolated.

O. chisosensis is protected by United 

States Federal Law and is protected 

within Big Bend National Park, but threats 

still exist, including insect and disease 

damage and climate change. The oakpine woodlands in which this species 

occurs are heavily-timbered and also 

subject to wildfires, the intensity and 

size of fires has been increasing in the 

distributional region of this species due 

to recent droughts. Drought also threatens to dry out streams and moist slopes 

which this species relies upon to survive. 

This species is a tree to 12 m, occurring 

in canyons along stream sides and on 

moist slopes. 

This species is ranked as G5T2 on 

NatureServe, using a place holder name 

Ostrya virginiana var. 1 (var. 1 in place 

of Ostrya virginiana var. chisosensis, 

a widely accepted synonym for this 

taxon, but it has not been published). 

Personal communication with staff at 

Big Bend National Park reports there 

are 8 occurrences, but several of these 

locations were last visited in 1993. Field 

surveys are recommended to ensure 

these subpopulations are still present. 

NatureServe also reports 2 occurrences 

in Mexico, but there is no published 

documentation of these occurrences. 

Refs: 11, 14, 44, 74, 133, 143, 161, 

196, 208, 222, 224, 226, 227, 230, 231

Assessor: Stritch, L.

currently little financial or administrative 

support available to reverse this trend. 

A continuing decline in the area, extent 

and quality of habitat is inferred from 

the overall continuing decline in forested 

areas in Georgia.

To ensure survival of this species, 

population monitoring is required, along 

with the identification and establishment 

of new protected areas.

This species is listed as Vulnerable in 

the Red List of Georgia (2006) and by 

the IUCN/SSC Caucasus Plant Red 

List Authority in 2007. No additional 

information contradicting this assessment has been found. The assessment 

therefore remains unchanged.

Refs: 74, 133, 208

Assessor: IUCN/SSC Caucasus Plant 

Red List Authority

CR B1ab(i,ii,iii,iv,v)+B2ab(i,ii,iii,iv,v)

United States (Texas)

Endemic to the United States, Ostrya 

chisosensis is known from eight occurrences in Big Bend National Park in 

Texas, with an extent of occurrence 

of approximately 20.5 km2

. The eight 

subpopulations occur in geographically 

separated canyons and are therefore 

reproductively isolated. The area of 

occupancy is 4.0 km2

. The population 

size is 639 mature individuals with 

around 150 mature individuals in the 

largest subpopulation. 

Based on inaccessibility, populations 

are thought to be stable, however catastrophic wildfire has been identified as 

being able to cause loss of any and/or 

all eight subpopulations. The overstorey 

vegetation in the canyons is oak-pine 

and is subject to very intense wildfires. 

The climate in the southwestern United 

States is becoming drier and warmer. It 

can be inferred under these conditions 

that the chance of intense or catastrophic 

wildfires is greatly increased, especially 

in the next 150 years. Besides wildfire 

there is a high probability that the current 

plant communities in these canyons will 

change with the potential loss of the 

oak pine overstorey and the concurrent 

loss of moist slopes and streamside 

habitats leading to the loss of O. chisosensis to taxa adapted to drier and warmer 

climate.

During the Pliocene/Pleistocene era, the 

Arcto-tertiary geoflora extended southward in to the mountains of the American 

southwest and adjacent Mexico. As 

the Pleistocene Era came to a close 

the climate became warmer and drier. 

Tree taxa such as O. knowltonii and 

O. chisosensis became restricted to 

canyons, occurring in the understorey 
The Red List of Betulaceae

31

Ostrya rehderiana Chun

CR B1ab(i,ii,v)+2ab(i,ii,v); C2a(i); D

China (Zhejiang: Tianmu Shan)

Endemic to China, this species occurs 

only in the western part of Tianmu 

Mountain (Mount Xitianmu) in the 

Zhejiang Province. It has an estimated 

extent of occurrence (EOO) and area of 

occupancy (AOO) of 0.04 km2

.

The only species of the genus Ostrya

occurring in eastern China, Ostrya 

rehderiana was once a fairly common 

species in the woods of Tianmushan 

(Tianmu Mountains) when it was 

discovered there in 1927. However, 

it is now considered extremely rare. 

This reduction in population size has 

been rapid, with the wild population 

now reported as consisting of only five 

individual trees confined to the western 

part of the mountain. All five individuals 

have experienced damage to either 

the trunk or branches, one of them 

(1 m DBH) has had the top of its trunk 

broken and the other four have had 

their lower lateral branches cut off. 

The rapid reduction in population of this 

species is mainly due to deforestation 

and the planting of bamboo. The major 

threats to this species in the wild are 

human disturbance and competition 

with bamboo and other tree species. 

Continued human disturbance can 

weaken regenerative ability and reduce 

the number of seedlings beneath the 

remaining mature individuals. As O. 

rehderiana is shade intolerant competition from nearby trees is of particular 

concern, especially bamboo which is a 

fast growing species reaching full size 

within 3–4 months. 

There is low genetic variation in the 

remaining 5 individuals. Offspring from 

the remaining individuals have been 

found to have experienced inbreeding 

and have reduced genetic variation, 

which can threaten the overall survival 

of the species by reducing the ability to 

adapt to a changing environment. It is 

advisory to reproduce each remaining 

individual via asexual reproduction, to 

reduce the risk of the permanent loss of 

genetic variation if one individual were 

to die, and then set up propagation and 

reintroduction programmes.

West Tianmu Mountain has been 

declared a nature reserve and stone 

fences have been erected around the 

remaining individuals of this species. 

However, despite these efforts, the 

wild populations do not appear to be 

regenerating naturally. 

This species is rare in cultivation, but 

is reported to occur in a few arboreta 

and botanic gardens outside of its 

natural range. The Arnold Arboretum of 

Harvard University, U.S., has cultivated 

a collection of 11 living specimens of this 

species collected from Mount Xitianmu.

This deciduous tree occurs in broadleaved forests and can grow to 21 m 

in height. The male inflorescences bud 

in July and blossom in April; the female 

inflorescences appear while buds are 

developing and leaves completely 

unfold in April. The fruits ripen in 

September and leaves fall in November.

This species was listed as Critically 

Endangered (D1) in the 1998 World List 

of Threatened Trees. The same conservation category (Critically Endangered) 

is given here. New updated information 

on its population size and range, more 

criteria (B, C and D) have now been 

able to be used to assess this species.

Refs: 11, 42, 74, 99, 121, 123, 133, 

155, 171, 208, 248
The Red List of Betulaceae

32

Betulaceae taxa evaluated as data deficient

Additional research is needed to gather information on the status of taxa assessed as Data Deficient. Many taxa assessed as 

Data Deficient have very small reported distributions. As an insurance policy, all Data Deficient taxa should be considered under

threat until sufficient information is available to fully assess their conservation status, or taxonomic uncertainty is resolved. 

The following taxa are assessed as threatened on the Chinese Red List. However very little information is available on these taxa 

and they are therefore assessed as Data Deficient. Further research and conservation action is required for these taxa which 

have small reported distributions and are likely to be threatened. 

Category 

on Chinese 

Red List

Carpinus purpurinervis Hu

China (Guangxi: Du’an Taozu Zizhixian, Guizhou: Dushan Xian, Xingyi Xi)

A small tree to 5 m, found growing in sparse forests or thickets on limestone. Distribution is restricted to two provinces in China. 

Potentially threatened but needs further field research to establish its conservation status. 

Refs: 42, 74, 99, 133, 208

VU

Corylus wangii Hu

China (Sichuan?, Yunnan: Weixi Xian)

Known only from NW Yunnan, with a possible specimen type collected from E Sichuan in 1988. A tall tree up to 7 m, found 

growing in temperate broad-leaved forests. Potentially threatened but requires further field research.

Refs: 42, 74, 99, 133, 208, 222, 242

VU

Ostrya yunnanensis W.K.Hu

China (Yunnan: Luquan Xian)

Known only from the Luquan Xian region of Yunnan, it grows up to 20 m, in moist forests at 2,600 m ASL. Further field research 

is needed to establish its conservation status.

Refs: 42, 56, 74, 75, 99, 107, 133, 208, 222

CR

Ostryopsis nobilis Balf.f. & W.W.Sm.

Taxonomic note: Populations found in north west Yunnan previously ascribed to Ostryopsis nobilis are now recognised as a new 

species O. intermedia

China (SW Sichuan, NW Yunnan)

A small shrub to 5 m, forming thickets on sunny mountain slopes. Distribution is restricted to SW Sichuan and NW Yunnan 

with populations described as sparse. Potentially threatened with habitat loss, but requires further field research to establish its 

conservation status.

Refs: 42, 74, 99, 133, 168, 208, 222, 253

VU

Betula schmidtii Regel

China (E Jilin: Linjiang, NE Liaoning), Democratic People’s Republic of Korea, Japan (N and C Honshu), Republic of Korea, 

Russian Federation (Central Asian Russia: Primoryi)

In the wild this species is able to grow up to 35 m tall and 9 m in girth, making it the tallest growing Birch. In the mountains of 

Korea it forms gnarled, mulit-stemmed trees and is much smaller. It is found growing in rocky places in the mountains, in mixed 

forest. Although widespread, it is reported as rare in Russia and to be threatened in China. It is also rare in cultivation. This 

species is considered potentially threatened, but requires further field research to establish its conservation status. 

Refs: 5, 42, 74, 99, 113, 114, 133, 154, 159, 208, 222

NT

The following species are assessed as 

Data Deficient as not enough information is 

available to carry out a full conservation 

assessment. Infraspecific taxa (even if given

a Data Deficient rating) are presented 

below the species-level assessment 

(see Globally Threatened Betulaceae 

taxa, pages 15 - 31 and Least Concern 

Betulaceae taxa, pages 37 - 53).

Alnus djavansnameshirii H.Zare

N Islamic Republic of Iran

A large tree reaching 20–30 m in height, 

this species has a limited geographical 

distribution, known only from Dodangeh 

forest. It is reported to be very rare, but 

there is limited population information 

available for this species. There is insufficient information available to carry out 

a full conservation assessment.

Refs: 74, 250

Alnus dolichocarpa H.Zare, Amini & 

Assadi

N Islamic Republic of Iran

A small to large tree found only near the 

Caspian Sea, this species is considered 

relatively rare. However, there is insufficient information available to carry out 

a full conservation assessment of this 

species.

Refs: 74, 250

Alnus fauriei H.Lév. & Vaniot

Japan (N and C Honshu)

A large shrub capable of achieving treestature, A. fauriei grows on soils with 

permanent moisture. This species is reported to be a recent introduction to 

cultivation, but is not commonly grown. 

Further research is needed to determine 

the conservation status of this species.

Refs: 74, 77, 133, 154, 208

Alnus firma Siebold & Zucc.

Japan (Kyushu)

This species has a small natural distribution but has been used extensively 

to control erosion and improve soil 
The Red List of Betulaceae

33

conditions in Korea, outside of its 

natural range. It has spread from 

planting sites and become naturalized, 

implying that natural regeneration 

is not a problem for this species. 

However, limited information is available 

on the status of wild populations of this 

species within its natural range. This 

species is therefore assessed as Data 

Deficient.

Refs: 74, 133, 154, 159, 208, 222

Alnus glutipes (Jarm. ex Czerpek) 

Vorosch.

Russian Federation (Central Asian 

Russia: Yakutiya)

Occurring as a shrub or tree, this 

species is found in mountain-taiga 

forests. However, there is insufficient 

information available to carry out a full 

conservation assessment. Further field 

research is required.

Refs: 74, 133, 208

Alnus hakkodensis Hayashi

Japan (Honshu)

Occurring as a shrub or tree, this 

species 

is found in the mountains of Honshu. 

This species was assessed as Rare in 

the 1997 IUCN Red List of Threatened 

Plants, but is assessed as Data Deficient 

in the Red List of Threatened Plants of 

Japan . Further field research is required 

for a full conservation assessment to be 

undertaken. 

Refs: 74, 132, 133, 208, 211, 236

Alnus lanata Duthie ex Bean

China (W Sichuan: Kangdang Xian, 

Luding Xian)

A tree to 20 m tall it is found on stream 

sides in montane forests. However, 

there is insufficient information available 

to carry out a full conservation assessment. Further field research is required.

Refs: 42, 74, 77, 133, 208, 222

Alnus mairei H. Lév.

China (Yunnan)

This species has a small reported 

distribution occurring only in one region 

of China. It is not assessed on the 

Chinese Red List. There is insufficient 

information available to carry out a full 

conservation assessment. Further field 

research is required.

Refs: 74, 99, 133, 208

Alnus maximowiczii Callier

Cyprus, Islamic Republic of Iran, Israel, 

Jordan, Lebanon, Syrian Arab Republic, 

Turkey in Asia

Insufficient information is available on 

the distribution or population status of

A. orientalis across its range, although 

threats are reported to be impacting 

upon part of the range of this species. 

This species is therefore assessed as 

Data Deficient. Further field research is 

required to verify the current distribution, population and threat status of this 

species.

Refs: 46, 54, 74, 133, 136, 208, 222, 

250

Alnus paniculata Nakai

Democratic People’s Republic of Korea, 

Republic of Korea

This species has a small reported distribution. There is insufficient information 

available to carry out a full conservation 

assessment. Further field research is 

required.

Refs: 74, 133, 208

Alnus serrulatoides Callier

Japan (S Honshu, Shikoku)

A small tree to 5 m. This species has 

a small reported distribution. There is 

insufficient information available to carry 

out a full conservation assessment. 

Further field research is required.

Refs: 74, 133, 154, 208

Alnus sieboldiana Matsum.

Alnus maximowiczii growing at Stone Lane 

Gardens. Data Deficient (Bartlett, P., Stone Lane 

Gardens)

Alnus maximowiczii

Democratic People’s Republic of Korea, 

Japan (Hokkaido, Honshu), Republic 

of Korea, Russian Federation (Central 

Asian Russia: Kurile Islands?, Primoryi, 

Sakhalin; European Russia: Khabarovsk)

Despite a fairly wide range, this species 

is reported to be scarce and seldom 

seen. There is insufficient information 

available to carry out a full conservation 

assessment. Further field research is 

required.

Refs: 74, 133, 154, 159, 208, 222

Alnus orientalis Decne.

Taxonomic note: Alnus orientalis var. 

pubescens was listed as Rare and 

endemic to Turkey, but this variety has 

since been included in the species A. 

orientalis. 

Alnus sieboldiana

Japan (Honshu, Shikoku?, Nansei-shoto: Suwanose-jima?)

This tree is found in lowlands and foothills, 

especially in coastal areas. The distribution of this species is uncertain and no 
The Red List of Betulaceae

34

Betula fargesii Franch.

China (Chongqing, Hubei)

This species is reported as Least Concern on the Chinese Red List. However, 

Ashburner and McAllister report that this 

species is known only from [a] restricted 

area on both sides of the Sichuan/Hubei 

border and that its conservation status is 

uncertain, so it seems likely this species 

is rare in the wild. Part of its distribution 

is within Shennongjia Forest Reserve in 

West Hubei. This species is very rare 

in cultivation. Further field research is 

required to determine the conservation 

status of this species. 

Refs: 5, 42, 74, 99, 133

Betula honanensis S.Y.Wang & 

C.L.Chang

China (Henan)

This taxon is not listed by Ashburner and 

McAllister but are recognised by the 

World Checklist of Selected Plant Families. Due to the taxonomic uncertainty 

and very little information available on 

distribution and population status, it is 

assessed as Data Deficient and in need 

of further study.

Refs: 5, 74

Betula karagandensis V.N.Vassil.

Kazakhstan

This taxon is not listed by Ashburner and 

McAllister but are recognised by the 

World Checklist of Selected Plant Families. Due to the taxonomic uncertainty 

and very little information available on 

distribution and population status, it is 

assessed as Data Deficient and in need 

of further study.

Refs: 5, 74

Betula klokovii Zaver.

Ukraine

This taxon is not listed by Ashburner and 

McAllister but are recognised by the 

World Checklist of Selected Plant Families. Due to the taxonomic uncertainty 

and very little information available on 

distribution and population status, it is 

assessed as Data Deficient and in need 

of further study.

Refs: 5, 74

Betula corylifolia Regel & Maxim.

Japan (Honshu)

Despite a small distribution, this species 

is reported to be fairly widespread in 

the mountains of central Honshu. This 

species is considered the most distinct 

birch, probably not closely related to any 

other living species. This species needs 

further field research to determine distribution and threats.

Refs: 5, 74, 133, 154, 208, 222

Betula delavayi Franch.

Taxonomic notes: (1) B. delavayi, B. 

bomiensis, B. calcicola and B. potaninii

taxa are sometimes confused. However they are separable by their visible 

morphological characters, ploidy and 

geographical distribution (2) Confusion 

with other species, and simple misidentifications of such a poorly understood 

species, makes its complete distribution 

difficult to determine (3) B. delavayi var. 

polyneura closely resembles both B. 

delavayi and B. calcicola, but has more 

numerous veins, it may represent a 

distinct taxon (4) B. delavayi var. microstachya deserves further study

China (Gansu?, W Hubei?, Qinghai?, W 

Sichuan, E Xizang?, NW Yunnan)

This species is assessed as Least 

Concern on the Chinese Red List, but 

this species has uncertain distribution 

and Ashburner and McAllister report 

that its conservation status is uncertain. 

Further research is required to enable 

a full conservation assessment to be 

carried out.

Refs: 5, 42, 74, 75, 77, 99, 123, 133, 

208

Betula falcata V.N. Vassil.

Tajikistan

This taxon is not listed by Ashburner 

and McAllister but are recognised by 

the World Checklist of Selected Plant 

Families. Due to the taxonomic uncertainty and very little information available 

on distribution and population status, 

it is assessed as Data Deficient and in 

need of further study.

Refs: 5, 74

population or threat information is available. Further field research is required.

Refs: 74, 77, 133, 154, 208, 222

Alnus vermicularis Nakai

Democratic People’s Republic of Korea, 

Republic of Korea

This species has a small reported distribution. There is insufficient information 

available to carry out a full conservation 

assessment. Further field research is 

required.

Refs: 74, 133, 208

Betula baschkirica Tzvelev

East European Russia

This taxon is not listed by Ashburner 

and McAllister but are recognised by 

the World Checklist of Selected Plant 

Families. Due to the taxonomic uncertainty and very little information available 

on distribution and population status, 

it is assessed as Data Deficient and in 

need of further study.

Refs: 5, 74

Betula celtiberica Rothm. & Vasc.

Taxonomic note: There is taxonomic uncertainty over whether this taxon should 

be recognised as a distinct species. Its 

geographical isolation and the fact that 

it can be distinguished morphologically 

suggests that it is worth recognising.

NW Spain (Cordillera Cantabrica)

Other populations of birch in isolated 

ranges in central Spain may belong to 

this species, but are thought more likely 

to be relict populations of B. pendula

or B. pubescens. Further field research 

is needed to verify the distribution and 

population status of this species to 

enable a full conservation assessment 

to be carried out.

Refs: 5, 74, 133, 163

Betula coriaceifolia V.N. Vassil.

Uzbekistan

This taxon is not listed by Ashburner and 

McAllister but are recognised by the World 

Checklist of Selected Plant Families. Due 

to the taxonomic uncertainty and very 

little information available on distribution 

and population status, it is assessed as 

Data Deficient and in need of further study.

Refs: 5, 74
The Red List of Betulaceae

35

Betula kotulae Zaver.

Ukraine

This taxon is not listed by Ashburner 

and McAllister but are recognised 

by the World Checklist of Selected 

Plant Families. Due to the taxonomic 

uncertainty and very little information 

available on distribution and population 

status, it is assessed as Data Deficient 

and in need of further study.

Refs: 5, 74

Betula potamophila V.N.Vassil.

Tajikistan

This taxon is not listed by Ashburner 

and McAllister but are recognised 

by the World Checklist of Selected 

Plant Families. Due to the taxonomic 

uncertainty and very little information 

available on distribution and population 

status, it is assessed as Data Deficient 

and in need of further study.

Refs: 5, 74

Betula psammophila V.N.Vassil.

Kazakhstan

This taxon is not listed by Ashburner 

and McAllister but are recognised 

by the World Checklist of Selected 

Plant Families. Due to the taxonomic 

uncertainty and very little information 

available on distribution and population 

status, it is assessed as Data Deficient 

and in need of further study.

Refs: 5, 74

Betula saksarensis Polozhij & 

A.T.Malzeva

Central Asian Russia: Krasnoyarsk

This taxon is not listed by Ashburner 

and McAllister but are recognised 

by the World Checklist of Selected 

Plant Families. Due to the taxonomic 

uncertainty and very little information 

available on distribution and population 

status, it is assessed as Data Deficient 

and in need of further study.

Refs: 5, 74

Betula saviczii V.N.Vassil.

Kazakhstan

This taxon is not listed by Ashburner 

and McAllister but are recognised by 

the World Checklist of Selected Plant 

Families. Due to the taxonomic uncertainty and very little information available 

on distribution and population status, 

it is assessed as Data Deficient and in 

need of further study.

Refs: 5, 74

Betula skvortsovii McAll. & Ashburner

Taxonomic note: Described for the first 

time by Ashburner and McAllister, 2013

China (Sichuan)

Shrub with several stems growing to 

2.5 m, this species grows on dry slopes 

and thickets. There is insufficient information available to carry out a full 

conservation assessment. Further field 

research is required.

Refs: 5, 25, 133

Betula sunanensis Y.J.Zhang

China (Gansu)

This taxon is not listed by Ashburner 

and McAllister but are recognised by 

the World Checklist of Selected Plant 

Families. Due to the taxonomic uncertainty and very little information available 

on distribution and population status, 

it is assessed as Data Deficient and in 

need of further study.

Refs: 5, 74

Betula wuyiensis J.B.Xiao

China (Fujian)

This taxon is not listed by Ashburner 

and McAllister but are recognised by 

the World Checklist of Selected Plant 

Families. Due to the taxonomic uncertainty and very little information available 

on distribution and population status, 

it is assessed as Data Deficient and in 

need of further study.

Refs: 5, 74

Betula zinserlingii V.N.Vassil

Kyrgyzstan

This taxon is not listed by Ashburner 

and McAllister but are recognised by 

the World Checklist of Selected Plant 

Families. Due to the taxonomic uncertainty and very little information available 

on distribution and population status, 

it is assessed as Data Deficient and in 

need of further study.

Refs: 5, 74

Carpinus dayongiana K.W.Liu & 

Q.Z.Lin

China (Hunan: Dayong Xian)

A small tree to 4 m found in subtropical 

broad-leaved forests. There is no 

quantitative data available from which 

to ascertain if the population trend is 

increasing, stable or decreasing across 

its geographic range.

Refs: 42, 74, 99, 133, 208

Carpinus eximia Nakai

Democratic People’s Republic of Korea, 

Republic of Korea

Very little information is available for this 

species. Field research is required to 

determine its conservation status.

Refs: 74, 133, 208

Carpinus faginea Lindl.

India (Himanchal Pradesh, JammuKashmir, Uttaranchal), Nepal

Found in cool broad-leaved forests in 

temperate Himalaya. There is insufficient information available to carry out 

a full conservation assessment. Further 

field research is required.

Refs: 21, 41, 74, 76, 133, 208, 222

Carpinus japonica Blume

Japan (Honshu, Kyushu, Shikoku)

This species can grow as a shrub or 

a tree. It is shade intolerant, therefore 

disturbance events are important for 

the seedling growth of this species. It 

grows at high elevations on the upper 

slope of valleys. It is reported to be rare, 

however insufficient data is available 

to carry out a full conservation assessment. Further field research is required.

Refs: 74, 133, 154, 193, 208, 222
The Red List of Betulaceae

36

Carpinus laxiflora (Siebold & Zucc.) 

Blume

There is insufficient information available 

to carry out a full conservation assessment. Further field research is required.

Refs: 74, 79, 106, 133, 208

Carpinus mengshanensis S.B.Liang & 

F.Z.Zhao

China (Shandong)

This species has a small distribution, 

restricted to one province of China. This 

species is assessed as Data Deficient 

on the Chinese Red List. There is 

insufficient information available to carry 

out a full conservation assessment. 

Further field research is required.

Refs: 74, 99, 133, 208

Carpinus microphylla Z.C.Chen ex 

Y.S.Wang & J.P.Huang

China (W Guangxi: Tianyang Xian)

A shrub to 3 m high this species grows 

in thickets. This species has a small 

distribution, restricted to one province 

of China. This species is assessed as 

Data Deficient on the Chinese Red List. 

There is insufficient information available 

to carry out a full conservation assessment. Further field research is required.

Refs: 42, 74, 99, 133, 208

Carpinus omeiensis Hu & W.P.Fang

China (Guizhou: Dejiang Xian, Sichuan: 

Emei Shanm Junlian Xian)

A tree to 7 m found in broad leaved 

forests. This species has a small 

distribution, restricted to two provinces 

of China. This species is not assessed 

on the Chinese Red List. There is 

insufficient information available to carry 

out a full conservation assessment. 

Further field research is required.

Refs: 42, 74, 77, 133, 208

Carpinus paohsingensis W.Y.Hsia

C and E China (exact locations unknown)

Found in evergreen forests at 1,500 m 

ASL. The distribution of this species is 

unknown. This species is not assessed 

on the Chinese Red List. There is 

insufficient information available to carry 

out a full conservation assessment. 

Further field research is required.

Refs: 74, 133, 208

Carpinus shimenensis C.J.Qi

China (Hunan)

This species has a small distribution, 

restricted to one province of China. 

This species is not assessed on the 

Chinese Red List. There is insufficient 

information available to carry out a full 

conservation assessment. Further field 

research is required.

Refs: 74, 133, 208

Corylus jacquemontii Decne.

Afghanistan?, India (Himachal Pradesh, 

Jammu-Kashmir, Uttaranchal), Nepal

A tall tree to 25 m, found growing in 

moist Oak forests of the upper montane 

zones. It is reported as rare in the 

Himalayan region. The wood can be 

used for agricultural implements and 

household articles, its nuts are edible 

and parts of the tree can be used as a 

medicinal tonic. Potentially threatened 

but requires further field research. 

Refs: 1, 21, 28, 68, 74, 133, 195, 208, 

222

Corylus potaninii Bobrov

China (Chongqing, Guizhou, Hubei, 

Sichuan, Yunnan)

This species is not assessed on the 

Chinese Red List. There is insufficient 

information available to carry out a full 

conservation assessment. Further field 

research is required.

Refs: 74, 133, 208

Ostryopsis intermedia B.Tian & 

J.Q.Liu

China (NW Yunnan)

A recently discovered species it grows 

as a small shrub to 5 m, forming 

thickets on sunny slopes. Only known 

from NW Yunnan, its population is 

sparce and likely threatened by habitat 

loss, plantations and over collection 

for building materials and fuelwood. 

Therefore this species is likely to be 

threatened but there is insufficient 

information available to carry out a full 

conservation assessment. Further field 

research is required.

Refs: 42, 74, 133, 208, 209

Carpinus laxiflora

Democratic People’s Republic of Korea, 

Japan (Hokkaido, Honshu, Kyushu, 

Shikoku), Republic of Korea

A tree to 15 m this species occurs in 

woodland in mountainous areas. There 

is insufficient information available to 

carry out a full conservation assessment. Further field research is required.

Refs: 74, 113, 133, 154, 208, 222

Carpinus lipoensis Y.K.Li

China (Guizhou)

This species has a small distribution, 

restricted to one province of China. 

This species is not assessed on the 

Chinese Red List. There is insufficient 

information available to carry out a full 

conservation assessment. Further field 

research is required.

Refs: 74, 133, 208

Carpinus luochengensis J.Y.Liang

China (Guangxi)

A shrub to a height of 2–3 m found 

growing in montane dwarf forest at 

mid to high altitudes. This species has 

a small distribution, restricted to one 

province of China. This species is not 

assessed on the Chinese Red List. 
The Red List of Betulaceae

37

Betulaceae taxa evaluated

as least concern

Most taxa have been assessed as Least 

Concern on the basis of their wide 

distribution and the lack of any direct 

threats to the species. For taxa that are 

less widespread additional information 

is provided to justify their assessment 

as Least Concern. (Data deficient 

infraspecific taxa are also listed here 

under the assessment of the species).

Alnus acuminata Kunth N Argentina 

(Catamarca, Jujuy, Salta, Tucumán), 

Bolivarian Republic of Venezuela, 

Colombia, Costa Rica, Ecuador, El 

Salvador, Guatemala, Honduras, 

Mexico (Chiapas, Chihuahua, Durango, 

Guanajuato, Guerrero, Hidalgo, Jalisco, 

México Distrito Federal, México State, 

Michoacán, Morelos, Nayarit, Oaxaca, 

Puebla, Querétaro, San Luis Potosí, 

Sinaloa, Sonora, Tlaxcala, Veracruz), 

Panama, Peru, Plurinational States of 

Bolivia

Refs: 24, 26, 29, 32, 58, 59, 60, 64, 74, 

77, 84, 87, 112, 117, 133, 140, 157, 

160, 178, 179, 208, 222, 235, 254

Alnus acuminata subsp. acuminata

Taxonomic note: There is some debate 

over the acceptance of this subspecies.

N Argentina (Jujuy, Salta, Tucumán), 

Bolivarian Republic of Venezuela, 

Colombia, Ecuador, Peru, Plurinational 

States of Bolivia

Refs: 24, 26, 32, 64, 74, 77, 84, 112, 

133, 157, 222

Alnus acuminata subsp. arguta

(Schltdl.) Furlow

Taxonomic note: There is some debate 

over the acceptance of this subspecies.

Costa Rica, El Salvador, Guatemala, 

Honduras?, Mexico (Chiapas, Chihuahua?, Durango, Guanajuato, Guerrero,

Hidalgo, Jalisco, México Distrito 

Federal, México State, Michoacán,

Morelos, Nayarit, Oaxaca, Puebla,

Querétaro, San Luis Potosí, Sinaloa,

Sonora, Veracruz), Panama

Refs: 24, 29, 59, 64, 74, 77, 87, 133, 

140, 144, 178, 179, 208, 222, 235

Alnus acuminata subsp. glabrata 

(Fernald) Furlow

Taxonomic note: There is some debate 

over the acceptance of this subspecies.

Mexico (Chiapas?, Durango, Guanajuato, 

Guerrero, Hidalgo, México Distrito 

Federal, México State, Michoacán, 

Morelos, Oaxaca, Puebla, Querétaro?, 

Sinoloa, Tlaxcala, Veracruz?)

Refs: 24, 29, 59, 64, 74, 77, 133, 208

Assessor: Stritch, L.

ensure this species does not become 

threatened in future. This species is 

assessed as Least Concern on the 

Chinese Red List.

Refs: 42, 74, 92, 99, 133, 205, 206, 

208, 245

Alnus ferdinandi-coburgii

C.K.Schneid.

China (Guizhou, SW Sichuan, Yunnan)

This species is assessed as Least 

Concern on the Chinese Red List.

Refs: 42, 74, 77, 99, 107, 133, 208

Alnus formosana (Burkill) Makino

Province of China (Taiwan: Tanshui)

Although this species has a fairly small 

distribution, found only in Taiwan, it 

is not currently subject to any major 

threats and the population is not predicted to decline in the near future. This 

species is assessed as Least Concern

on the Chinese Red List.

Refs: 42, 74, 77, 82, 91, 94, 99, 133, 

208, 222

Alnus glutinosa (L.) Gaertn.

Alnus glutinosa subsp. glutinosa

Albania, Algeria, Armenia?, Austria, 

Azerbaijan?, Belarus, Belgium, Bosnia 

and Herzegovina, Bulgaria, Croatia, 

Czech Republic, Denmark, Estonia, 

Finland, France (inc. Corsica), Georgia, 

Germany, Greece, Hungary, Islamic 

Republic of Iran, Italy (inc. Sardegna, 

Sicilia), Kazakhstan, Latvia, Libya?, 

Liechtenstein, Lithuania, Luxembourg, 

Montenegro, Morocco, Netherlands, 

Norway, Poland, Portugal, Romania, 

Russian Federation (Eastern Asian 

Russia: West Siberia; European Russia: 

Central European Russia, Chechnya, 

Dagestan, East European Russia, 

Ingushetiya, Kabardino-Balkariya, 

Karachaevo-Cherkessiya, Krasnodar, 

North European Russia, Northwest 

European Russia, Servero-Osetiya, 

South European Russia, Stavropol), 

Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, The Former Yugoslav 

Republic of Macedonia, Tunisia, Turkey 

in Asia, Turkey in Europe, Ukraine (inc. 

Krym), United Kingdom (Great Britain, 

Northern Ireland) (The species and type 

subspecies share the same distribution).

Refs: 4, 12, 16, 19, 20, 23, 40, 43, 44, 

71, 74, 102, 116, 131, 133, 138, 146, 

149, 170, 189, 208, 222, 223, 224, 

233, 238, 243, 249

Alnus cordata (Loisel.) Duby

NW Albania, France: Corsica, Southern 

Italy (inc. Sicily)

This species has a limited natural 

range, but most of the range of this 

species occurs in protected areas. It 

also spreads readily and rapidly, and 

has become naturalised in much of 

Europe. It is therefore not considered 

to be threatened, however some 

threats have been identified, including; 

a reduction in clear cutting practices 

in protected areas which could have a 

negative impact on population growth, 

competition from other species, climate 

change at lower altitudes, and root rot 

caused by the pathogen Phytophthora 

alni. Active conservation management 

within protected areas and population 

studies are advised for this species, to 

ensure it does not become threatened 

in future. 

Refs: 11, 74, 102, 133, 136, 157, 170, 

208, 222, 238

Alnus cremastogyne Burkill

China (SE Gansu, N Guizhou, S Shaanxi, 

Sichuan, Zhejiang)

This species is endemic to south 

western China with a fairly small natural 

distribution. Although there are some 

reported threats impacting the survival 

of this species in parts of its range, it 

grows rapidly and has a rapid regeneration rate. It is also being planted at 

restoration sites within its natural range. 

This species is therefore not considered 

to be threatened, but monitoring of 

reported threats would be beneficial, to 

Alnus cordata
The Red List of Betulaceae

38

Alnus glutinosa subsp. antitaurica 

Yalt.

DD

N Islamic Rupublic of Iran, SC Turkey 

(Turkey in Asia)

This little known subspecies occurs 

as a shrub or tree found in deciduous 

scrub or forest areas by streams. This 

subspecies has been previously listed 

as rare in national and regional red 

list publications, but at the time was 

thought to be endemic to Turkey. It has 

since been reported as present in Iran, 

but there is insufficient data available 

to carry out a full conservation assessment. Further research is required and it 

is assessed here as Data Deficient.

Refs: 46, 47, 54, 74, 133, 250

Alnus glutinosa subsp. barbata

(C.A.Mey.) Yalt.

DD

Armenia?, Azerbaijan?, Georgia, Islamic 

Republic of Iran, Russian Federation 

(European Russia: Chechnya, Dagestan, Ingushetiya, Kabardino-Balkariya, 

Karacheyevo-Cherkessiya, Krasnodar, 

Severo-Osetiya, Stavropol), Turkey in 

Asia

This species occurs as a shrub or tree 

found in damp woods and along river 

banks. There is insufficient information 

available to carry out a full conservation 

assessment. Further field research is 

required. It is assessed here as Data 

Deficient.

Refs: 15, 30, 74, 133, 208

Alnus glutinosa subsp. betuloides

Ansin

DD

SE Turkey (Turkey in Asia)

A little known subspecies which occurs 

as a shrub or tree, this taxon is restricted to the mountains of East Anatolia in 

Erzurum, Bingöl and Bitlis Provinces. 

It is found by streams and swamps. 

This species was assessed as Rare in 

the 1997 IUCN Red List of Threatened 

Plants (ref 236). However, there is 

insufficient information available to carry 

out a full conservation assessment. 

Further field research is required.

Refs: 47, 74, 80, 133, 236

Alnus hirsuta (Spach) Rupr. New York, North Dakota, Ohio, Oregon, 

Pennsylvania, Rhode Island, Utah, 

Vermont, Virginia, Washington, West 

Virginia, Wisconsin, Wyoming).

Alnus incana is ranked G5 (Globally 

secure) on NatureServe.

Refs: 4, 40, 44, 48, 64, 71, 74, 81, 89, 

97, 110, 115, 116, 131, 133, 136, 138, 

143, 149, 172, 186, 189, 208, 212, 

217, 221, 222, 223, 224, 225, 233, 

237, 238, 249

Alnus incana subsp. incana

Albania, Armenia, Austria, Azerbaijan, 

Belarus, Bosnia and Herzegovina, 

Bulgaria, Croatia, Czech Republic, 

Estonia, Finland, France, Georgia, 

Germany, Greece?, Hungary, Italy, 

Latvia, Lithuania, Moldova, Montenegro, 

Netherlands, Norway, Poland, Romania, 

Russian Federation (Eastern Asian 

Russia: West Siberia; Central European 

Russia, Chechnya, Dagestan, East 

European Russia, Ingushetiya, Kabardino-Balkariya, Karacheyevo-Cherkessiya, Krasnodar, North European 

Russia, Severo-Osetiya, South European Russia, Stavropol), Serbia, Slovakia, 

Slovenia, Sweden, Switzerland, The 

Former Yugoslav Republic of Macedonia, Turkey in Asia, Ukraine.

Alnus incana subsp. incana is ranked as 

G5T5 (Globally secure) on NatureServe.

Refs: 64, 74, 133, 222, 224

Alnus incana subsp. rugosa (Du Roi) 

R.T.Clausen

Canada (Labrador, Manitoba, New 

Brunswick, Newfoundland, Nova Scotia, Nunavut, Ontario, Prince Edward 

Island, Québec, Saskatchewan), Saint 

Pierre and Miquelon, United States 

(Connecticut, Illinois, Indiana, Iowa, 

Maine, Maryland, Massachusetts, Michigan, Minnesota, New Hampshire, New 

Jersey, New York, North Dakota, Ohio, 

Pennsylvania, Rhode Island, Vermont, 

Virginia, West Virginia, Wisconsin)

Refs: 44, 64, 74, 81, 133, 143, 172, 

186, 208, 217, 221, 222, 223, 224, 

225, 233, 237

Alnus incana subsp. tenuifolia (Nutt.) 

Breitung

Canada (Alberta, British Columbia, 

Northwest Territories, Saskatchewan, 

Yukon), United States (Alaska, Arizona, 

China (Heilongjiang, Jilin, Liaoning, 

Nei Mongol, Shandong), Democratic 

People’s Republic of Korea, Japan 

(Hokkaido, Honshu, Kyushu, Shikoku), 

Republic of Korea, Russian Federation 

(Central Asian Russia: Amur, Buryatiya, 

Chita, Kamchatka, Magadan, Primoryi, 

Sakhalin, Yakutiya; European Russia: 

Khabarovsk)

Refs: 42, 74, 99, 133, 136, 154, 159, 

180, 208, 222

Alnus incana (L.) Moench

Albania, Armenia, Austria, Azerbaijan, 

Belarus, Bosnia and Herzegovina, Bulgaria, Canada (Alberta, British Columbia, 

Labrador, Manitoba, New Brunswick, 

Newfoundland, Northwest Territories, 

Nova Scotia, Nunavut, Ontario, Prince 

Edward Island, Quebec, Saskatchevan, 

Yukon), Croatia, Czech Republic, Estonia, 

Finland, France, Georgia, Germany, 

Greece?, Hungary, Italy, Latvia, Liechtenstein, Lithuania, Moldova, Montenegro, 

Netherlands, Norway, Poland, Romania, 

Russian Federation (Eastern Asian Russia: 

West Siberia; Central European Russia, 

Chechnya, Dagestan, East European 

Russia, Ingushetiya, Kabardino-Balkariya, 

Karacheyevo-Cherkessiya, Krasnodar, 

North European Russia, Northwest European Russia?, Severo-Osetiya, South 

European Russia, Stavropol), Saint Pierre 

and Miquelon, Serbia, Slovakia, Slovenia, 

Sweden, Switzerland, The Former Yugoslav Republic of Macedonia, Turkey 

in Asia, Ukraine, United States (Alaska, 

Arizona, California, Colorado, Connecticut, Idaho, Illinois, Indiana, Iowa, Maine, 

Maryland, Massachusetts, Michigan, 

Minnesota, Montana, Nevada, New 

Hampshire, New Jersey, New Mexico, 

Alnus hirsuta
The Red List of Betulaceae

39

California, Colorado, Idaho, Montana, 

Nevada, New Mexico, Oregon, Utah, 

Washington, Wyoming).

Alnus incana subsp. tenuifolia is 

ranked as G5T5 (globally secure) on 

NatureServe.

Refs: 44, 64, 74, 133, 143, 186, 208, 

217, 221, 222, 224, 225, 233

Alnus incana subsp. kolaensis (Orlova) 

Á.Löve and D.Löve

DD

Taxonomic note: the taxonomic status 

of this species is uncertain.

Finland, Norway, Russian Federation 

(European Russia: Northwest European 

Russia)?, Sweden

A tree found growing in river valleys, 

frequently found bordering boreal or 

alpine areas and can also be found in 

shrub tundra in the bordering Arctic. 

This is a little known subspecies. It is 

assessed here as Data Deficient.

Refs: 48, 74, 97, 133, 143, 208, 212

Assessor: Stritch, L.

Alnus japonica (Thunb.) Steud.

China (Anhui, Hebei, Henan, Jiangsu, 

Jilin, Liaoning, Shandong), Democratic 

People’s Republic of Korea, Japan 

(Hokkaido, Honshu, Kyushu, Ryukyu 

Islands, Shikoku), Province of China 

(Taiwan), Republic of Korea, Russian 

Federation (Central Asian Russia: Kurile 

Islands?, Primoryi, Sakhalin)

Refs: 42, 74, 99, 120, 133, 157, 159, 

208, 222

Alnus jorrullensis Kunth Guatemala?, 

Honduras, Mexico (Chiapas, Colima, 

Durango, Guanajuato, Guerrero, Hidalgo, Jalisco, México Distrito Federal, 

México State, Michoacán, Morelos, 

Oaxaca, Puebla, Queretaro, Sinaloa,

Veracruz, Zacatecas)

Refs: 29, 33, 59, 64, 74, 133, 140, 145, 

147, 160, 208, 222, 235

Alnus jorullensis subsp. jorullensis

DD

Guatemala?, Honduras, Mexico 

(Chiapas, Colima, Durango, Guerrero, 

Hidalgo, Jalisco, México Distrito 

Federal, México State, Michoacán, 

Morelos, Oaxaca, Puebla, Veracruz)

This is a little known taxon, with a 

fairly wide range within Mexico, but its 

distribution is restricted to high altitudes 

(2,300 m to 3,800 m ASL). Climate 

change may therefore present a threat 

to this taxon. It is assessed here as 

Data Deficient.

Refs: 64, 59, 74, 133, 145

Alnus jorullensis subsp. lutea Furlow 

DD

Mexico (Colima, Durango, Guanajuato, 

Guerrero, Hidalgo, Jalisco, México Distrito Federal, México State, Michoacán, 

Morelos, Oaxaca, Puebla, Queretaro, 

Sinaloa, Veracruz, Zacatecas)

This is a Little known taxon, with a 

fairly wide range within Mexico, but its 

distribution is limited to along streams in 

areas between 1,000 m and 2,500 m 

ASL. It is assessed here as Data 

Deficient.

Refs: 59, 74, 133, 208

Assessor: Stritch, L.

Alnus mandshurica (Callier) Hand.-

Mazz.

China (Heilongiang, Jilin, Liaoning, Nei 

Mongol), Democratic People’s Republic 

of Korea, Republic of Korea, Russian 

Federation (Central Asian Russia: 

Primoryi; European Russia: Khabarovsk)

Refs: 42, 74, 77, 99, 133, 159, 208, 

222

Alnus matsumurae Callier

Japan (N and C Honshu)

This tree species has a small distribution, but it is reported to be common 

across its range. Due to its relatively 

small range, monitoring is recommended to ensure populations remain stable. 

Refs: 74, 77, 133, 208, 222

Alnus nepalensis D.Don

Bangladesh, Bhutan, China (Guangxi, 

Guizhou, SW Sichuan, Xizang, Yunnan), 

India (Arunachal Pradesh, Assam, 

Darjiling, Himanchal Pradesh, Manipur, 

Meghalaya, Mizoram, Nagaland, Sikkim, 

Tripura, Uttaranchal), Myanmar, Nepal, 

N Thailand, N Vietnam

Refs: 3, 28, 37, 41, 43, 60, 68, 74, 83, 

99, 125, 133, 152, 157, 181, 191, 195, 

208, 222, 224, 234

Alnus nitida (Spach) Endl.

NE Afghanistan, India (Himachal 

Pradesh, Jammu-Kashmir, Uttaranchal), 

W and C Nepal, N Pakistan

Refs: 15, 37, 41, 45, 74, 125, 133, 208, 

222

Alnus oblongifolia Torr. 

Mexico (Chihuahua, Sonora), United 

States (Arizona, New Mexico)

This species is ranked G3G4 (Vulnerable/Apparently Secure) on NatureServe 

(ref 143).

Refs: 44, 64, 74, 133, 143, 161, 208, 

221, 222, 224, 225

Assessor: Stritch, L.

Alnus pendula Matsum.

Democratic People’s Republic of Korea, 

Japan (Hokkaido, Honshu), Republic of 

Korea

Refs: 74, 77 133, 154, 159, 208, 222, 

224

Alnus rhombifolia Nutt.

United States (California, Idaho, 

Montana, Nevada, Oregon, Washington)

This species is ranked G5 (Secure) on 

NatureServe (ref 143).

Refs: 44, 74, 90, 133, 143, 208, 217, 

221, 222, 224, 225, 233

Assessor: Stritch, L.

Alnus rubra Bong.

Canada (British Columbia, Yukon), 

United States (Alaska, California, Idaho, 

Montana, Oregon, Washington)

This species is ranked G5 (Secure) on 

NatureServe (ref 143).

Refs: 16, 44, 64, 74, 90, 133, 143, 157, 

165, 208, 217, 221, 222, 223, 224, 

225, 233, 224, 225, 233

Assessor: Stritch, L.

Alnus serrulata (Aiton) Willd.

Taxonomic note: this species has been 

erroneously called Alnus rugosa in a 

number of earlier floristic works. 

Canada (New Brunswick?, Nova Scotia, 

Québec), United States (Alabama, Arkansas, Connecticut, Delaware, District 

of Columbia, Florida, Georgia, Illinois, 

Indiana, Kansas?, Kentucky, Louisiana, 

Maine, Maryland, Massachusetts, 

Mississippi, Missouri, New Hampshire, 

Alnus pendula
The Red List of Betulaceae

40

West Siberia; European Russia: Central 

European Russia, Irkutsk, Khaborovsk, 

North European Russia), Serbia, 

Slovenia, Switzerland, The Former 

Yugoslav Republic of Macedonia, 

United States (Alaska, Aleutian Islands, 

California, Colarado, Idaho, Maine, 

Massachusetts, Michigan, Minnesota, 

Montana, New Hampshire, New York, 

North Carolina, Oregon, Pennsylvania, 

Tennessee, Vermont, Washington, 

Wyoming), Ukraine.

This species is ranked G5 (secure) on 

NatureServe.

Refs: 18, 44, 57, 62, 64, 71, 74, 81, 86, 

98, 111, 133, 139, 143, 167, 172, 182, 

186, 199, 208, 215, 217, 221, 222, 

223, 224, 233, 238

Alnus viridis subsp. viridis (Chaix) DC.

Austria, Bosnia and Herzegovina, 

Bulgaria, Czech Republic, France, 

Germany, Hungary, Italy, Macedonia, 

Poland, Romania, Serbia, Slovenia, 

Switzerland, Ukraine.

Refs: 215, 222

Alnus viridis subsp. crispa (Aiton) Turrill

Canada (Alberta, British Columbia, 

Manitoba, New Brunswick, Newfoundland, Northwest Territories, Nova Scotia, 

Nunavut, Ontario, Prince Edward Island, 

Quebec, Saskatchewan), Greenland, 

France (St. Pierre and Miquelon), United 

States (Alaska, Maine, Massachusetts, 

Michigan, Minnesota, New Hampshire, 

New York, North Carolina, Pennsylvania, 

Tennessee, Vermont, Wisconsin).

This taxon is not ranked (G5TNR) on 

NatureServe.

Refs: 44, 64, 74, 81, 143, 172, 186, 

208, 222, 224, 233

Alnus viridis subsp. fruticosa (Rupr.) 

Nyman

Taxonomic note: There is still some debate over the acceptance of the naming 

of this taxon. Alnus alnobetula subsp. 

fruticosa is sometimes considered the 

accepted name for this taxon.

Canada (Alberta, British Columbia, 

Northwest Territories, Saskatchewan, 

Yukon), China (Nei Mongol), Mongolia, 

Russian Federation (Altay, Amur, 

Arkhangelsk, Buryatiya, Chita, 

Gomo-Altay, Irkutsk, Kemerovo, 

Khabarovsk, Kirov, Komi, Krasnoyarsk, 

Magadan, Nenets, Novosibirsk, 

Omsk, Perm, Tomsk, Tuva, Tyumen, 

Yakutia-Sakha), United States (Alaska, 

California, Oregon, Washington)

This taxon is not ranked (G5TNR) on 

NatureServe (ref 143).

Refs: 44, 64, 74, 143, 186, 208, 215, 

222, 224, 233

Alnus viridis subsp. sinuata (Regel) 

Á.Löve & D.Löve

Taxonomic note: There is still some 

debate over the acceptance of the 

naming of this taxon. Alnus alnobetula 

subsp. sinuata is sometimes considered 

the accepted name for this taxon.

Canada (Alberta, British Columbia, 

Northwest Territories, Yukon), Russian 

Federation (Siberia), United States 

(Alaska, California, Idaho, Montana, 

Oregon, Washington, Wyoming) 

This taxon is ranked G5T5 (Secure) on 

NatureServe.

Refs: 44, 64, 74, 143, 182, 186, 208, 

217, 222, 223, 224, 233

Assessor: Stritch, L.

Betula alleghaniensis Britton

New Jersey, New York, North Carolina, 

Ohio, Oklahoma, Pennsylvania, Rhode 

Island, South Carolina, Tennessee, 

Texas, Vermont, Virginia, West Virginia).

This species is ranked G5 (Secure) on 

NatureServe (ref 143).

Refs: 43, 44, 64, 72, 74, 81, 133, 143, 

172, 186, 208, 221, 223, 224, 225, 

233, 237

Assessor: Stritch, L.

Alnus trabeculosa Hand.-Mazz.

China (Anhui, Fujian, N Guangdong, 

Guizhou, S Henan, Hubei, E Hunan, 

Jiangsu, Jiangxi, Zhejiang), Japan 

(Honshu).

This species is reported as rare in 

Japan, but it also occurs in China where 

it is not considered to be threatened. 

This species is therefore assessed as 

Least Concern, but population monitoring should be implemented in Japan 

and conservation action if necessary, to 

maintain genetic diversity across the full 

range of this species.

Refs: 42, 74, 77, 96, 99, 132, 133, 141, 

154, 208, 222, 224

Alnus viridis (Chaix) DC.

Taxonomic note: There is still some 

debate over the acceptance of the 

naming of this taxon. Many references 

report Alnus alnobetula as the accepted 

name. As this complex occurs in North 

America, the taxonomy used here 

reflects the taxonomy widely used in 

that region. This differs to the taxonomy 

of the World Checklist of Selected Plant 

Families and recognises only three 

subspecies; subsp. crispa, subsp. 

fruticosa and subsp. sinuata. The 

Alnus alnobetula complex recognises 

additional infraspecific taxa.

Austria, Belarus, Bosnia and Herzegovina, Bulgaria, Canada (Alberta, British 

Columbia, Labrador, Manitoba, New 

Brunswick, Newfoundland, Northwest 

Territories, Nova Scotia, Ontario, Prince 

Edward Island, Quebec, Saskatcheven, 

Yukon), China?, Croatia, Czech Republic, France (inc Corsica), Germany, 

Greenland, Hungary, Italy, Japan (Hokkaido, Honshu), Mongolia, Montenegro, 

Poland, Romania, Russian Federation 

(Central Asian Russia: Amur, Buryatiya, 

Chita, Kamchatka, Krasnoyarsk, Kurile 

Islands, Magadan, Primoryi, Sakhalin, 

Yakutiya; Eastern Asian Russia: Altay, 

Betula alleghaniensis

Canada (Labrador, New Brunswick, 

Newfoundland, Nova Scotia, Ontario, 

Prince Edward Island, Québec), Saint 

Pierre and Miquelon, United States 

(Connecticut, Georgia, Illinois, Indiana, 

Iowa, Kentucky, Maine, Maryland, 

Massachusetts, Michigan, Minnesota, 

New Hampshire, New Jersey, New 

York, North Carolina, Ohio, Pennsylvania, Rhode Island, South Carolina, 

Tennessee, Vermont, Virginia, West 

Virginia, Wisconsin)
The Red List of Betulaceae

41

This species is ranked G5 (Secure) on 

NatureServe.

Refs: 5, 16, 44, 51, 74, 90, 133, 143, 

172, 202, 208, 222, 224, 233

Assessor: Stritch, L.

Betula alnoides Buch.-Ham. ex D.Don

Bhutan, Bangladesh, China (Fujian, 

Guangxi, Hainan, Hubei, Sichuan, 

S Yunnan), India (Arunachal Pradesh, 

Assam, Darjiling, Himanchal Pradesh, 

Manipur, Meghalaya, Mizoram, 

Nagaland, Sikkim, Tripura, Uttaranchal), 

Laos, Myanmar, Nepal, Thailand, 

Vietnam

Refs: 5, 37, 41, 42, 56, 68, 64, 83, 99, 

125, 133, 152, 208, 222, 234

Betula ashburneri McAll. & Rushforth

conservation status of the full species 

complex is considered more secure.

Refs: 5, 42, 74, 99, 113, 133, 159, 208, 

222

Betula cordifolia Regel

Taxonomic note: until recently this 

species has been regarded as a variety 

of B. papyrifera. Studies confirm the 

diploid status of B. cordifolia, defined 

its morphological distinctness and 

suggest that it is likely to be one of 

the constituent genomes of hexaploid 

B. papyrifera.

Canada (Labrador, New Brunswick, 

Newfoundland, Nova Scotia, Ontario, 

Prince Edward Island, Quebec), Saint 

Pierre and Miquelon, United States 

(Connecticut?, Maine, Massachusetts, 

Michigan, Minnesota, New Hampshire, 

New York, North Carolina, Pennsylvania, 

Vermont, Virginia, Wisconsin, West 

Virginia)

Refs: 5, 44, 74, 77, 133, 222, 233

Betula costata Trautv. 

China (Hebei, Heilongjiang, Jilin, 

Liaoning, Nei Mongol), Democratic 

People’s Republic of Korea, Republic 

of Korea, Russian Federation (Central 

Asia Russia: Amur, Primoryi; European 

Russia: Khabarovsk)

Refs: 5, 42, 74, 99, 113, 133, 159, 208, 

222

Betula cylindrostachya Lindl. ex Wall.

Taxonomic notes: (1) This tetraploid 

species is often confused with the 

closely related diploid B. alnoides and 

B. luminifera. It can be distinguished 

from B. alnoides by its spring rather 

than autumn-winter flowering period, 

its wider fruiting catkins and more 

cordate leaf bases. B. luminifera is 

morphologically very similar, but has 

(usually) solitary female catkins (catkins 

are in groups of two to six in the other 

two species) (2) The recently described 

B. fujianensis would seem to be synonymous with B. cylindrostachya, the only 

significant difference being the glandular 

shoots and the absence of hair tufts in 

the secondary vein axils on the abaxial 

leaf surface (3) B. rhombibracteata is 

doubtfully distinct from 

B. cylindrostachya

Bhutan, China (SW Sichuan, NW 

Yunnan, Fujian), India (Arunanchal 

Bhutan, China (SW Sichuan, NW 

Yunnan, SE Xizang)

This species is known only from a few 

localities within its range. However, it is 

reported by Ashburner and McAllister 

(ref 5) to be ‘probably locally common’. 

Refs: 5, 9, 74, 127, 208

Betula chinensis Maxim.

Taxonomic note: This species has a 

morphologically distinct 6x cytotype 

known only from two high mountains in 

South Korea whose conservation status 

is uncertain. The species otherwise is 

8x which is common. Until more collections of both types have been checked 

and compared, and a geographical 

difference has emerged, the two types 

do not merit different names. 

China (E Gansu, Hebei, Henan, Liaoning, Nei Mongol, Shaanxi, Shandong, 

Shanxi), Democratic Republic of Korea, 

Republic of Korea

Ashburner and McAllister note that the 

conservation status of the 6x cytotype 

in South Korea is uncertain. The 

Taxonomic note: This species occurs as 

two cytotypes: the octoploid cytotype is 

common and widespread in continental 

north-eastern Asia including Korea, 

but the hexaploid is rare and found in 

Japan and the Kurile Island of Iturup. It 

has been proposed by Ashburner and 

McAllister (2013) that the continental 

octoploid cytotype is recognised as var. 

dahurica, the Kurile Island and Hokkaido 

populations as var. okuboi, and the 

more distinct Honshu populations as 

var. parvifolia

China (Hebei, Heilongjiang, E Jilin, 

N Liaoning, Nei Mongol, Shaanxi, Shanxi), 

Democratic People’s Republic of Korea, 

Japan (Hokkaido, Honshu), Republic of 

Korea, Mongolia, Russian Federation 

(Central Asian Russia: Amur, Buryatiya?, 

Chita, Kurile Islands, Primoryi; European 

Russia: Khabarovsk) 

(B. dahurica var. dahurica does not 

occur in Japan, otherwise its distribution matches the species)

B. dahurica is assessed as Vulnerable 

in Japan, but due to its wide distribution 

outside of Japan it is considered to be 

locally threatened in Japan, but not 

globally threatened. 

Refs: 5, 42, 74, 99, 128, 132, 133, 154, 

159, 208

Betula dahurica

Betula ashburneri growing in the Himalayas 

at 3,400 m

Pradesh, Assam, Darjiling, Himanchal 

Pradesh, Manipur, Meghalaya, Mizoram, 

Nagaland, Sikkim, Tripura, Uttaranchal), 

N Myanmar, Nepal, Pakistan

Refs: 5, 9, 42, 67, 74, 77, 83, 99, 133, 

208, 222

Betula dahurica Pall.
The Red List of Betulaceae

42

Betula dahurica var. dahurica

China (Hebei, Heilongjiang, E Jilin, 

N Liaoning, Nei Mongol, Shaanxi, Shanxi), 

Democratic People’s Republic of Korea

This taxon is reported to be common 

and widespread (see taxonomic note for 

B. dahurica).

Refs: 5, 74

Betula dahurica var. okuboi Miyabe & 

Tatew.

DD

Japan (Hokkaido), Russian Federation 

(Central Asian Russia: Kurile Islands)

This little known variety is reported to 

be rare in the wild (see taxonomic note 

for B. dahurica). It is assessed as Near 

Threatened in Japan, but insufficient 

information is available to carry out a full 

range wide conservation assessment. It 

is assessed here as Data Deficient and 

in need of further field research. 

Refs: 5, 74, 128, 133

Betula dahurica var. parvifolia

Ashburner & McAll.

DD

Taxonomic note: this is described as a 

new variety by Ashburner and McAllister 

(2013)

Japan (Honshu)

This taxon is known only from a small 

population near Nobeyama in Nagano 

Prefecture in the central part of the 

main island of Honshu, Japan. Cultivated living collections and all known 

herbarium specimens seem to be from 

the same locality. This taxon is reported 

as ‘not rare’ in the single locality that 

it is known from, however, only one 

seed bearing tree was found. The very 

restricted distribution of this taxon 

makes it vulnerable to natural disaster, 

including pest or disease outbreak, or 

human induced land clearance. Natural 

regeneration is also assumed limited as 

only one seed bearing tree has been 

reported from the remaining population. 

Additional fieldwork is recommended 

to ensure no other populations exist. 

As this taxon is only recently described 

there is very little published information 

about this taxon. Currently available 

information indicates this may threatened. Further field research is required 

to determine its conservation status. 

Refs: 5

Betula ermanii Cham. Taxonomic note: B. ermanii var. 

saitoana was previously described as 

threatened is no longer an accepted 

variety of B. ermanii

Betula ermanii var. ermanii

China (Heilongjiang, Jilin, Liaoning, Nei 

Mongol), Democratic People’s Republic 

of Korea, Japan (Hokkaido, Honshu, 

Shikoku), Republic of Korea, Russian 

Federation (Central Asian Russia: Amur, 

Buryatiya, Chita, Kamchatka, Kurile 

Islands?, Magadan, Primoryi, Sakhalin, 

Yakutiya; European Russia: Irkutsk, 

Khavarovsk)

Refs: 5, 42, 74, 99, 113, 133, 154, 159, 

208, 212, 222

Betula ermanii var. lanata Regel 

China (Heilongjiang, Jilin, Liaoning), 

Russian Federation (Central Asian Russia: Amur, Buryatiya, Chita, Magadan, 

Primoryi, Sakhalin, Yakutiya; European 

Russia: Irkutsk, Khabarovsk)

Refs: 5, 74, 133

Betula fruticosa Pall.

Taxonomic notes: (1) B. tatewakiana

is generally considered a minor variant 

of B. fruticosa (2) B. baicalensis is a 

possible hybrid between B. fruticosa 

and B. pendula (3) B. middendorfii and 

B. divaricata probably belong here, but 

are very similar to B. glandulosa from 

Goose Bay in Labrador

China (N Heilongjiang, Jilin?, Nei Mongol), 

Democratic People’s Republic of Korea, 

Mongolia, Japan (Hokkaido)?, Republic 

of Korea, Russian Federation (Central 

Asian Russia: Amur, Buryatiya, Chita, 

Kamchatka, Magadan, Primoryi, Sakhalin, 

Yakutiya; European Russia: Irkutsk, 

Khabarovsk) 

This species is assessed as Vulnerable 

in Japan under the synonym Betula 

ovalifolia. This species is therefore 

considered locally threatened in Japan, 

but due to its wider distribution outside 

of Japan it is not considered to be 

globally threatened.

Refs: 5, 42, 74, 99, 132, 133, 154, 159, 

208, 212, 222

Betula glandulosa Michx.

Taxonomic note: B. nana subsp. exilis

is here treated as a dwarf, mainly more 

northern, variant of B. glandulosa.

Canada (Alberta, British Columbia, 

Labrador, Manitoba, New Brunswick, 

Newfoundland, Northwest Territories, 

Betula ermanii 'Polar Bear'

Betula ermanii

Betula ermanii
The Red List of Betulaceae

43

Nova Scotia, Ontario, Prince Edward 

Island, Québec, Saskatchewan, Yukon), 

Greenland, Russian Federation (Central 

Asian Russia: Amur, Buryatiya, Kamchatka, Krasnoyarsk, Kuril Islands?, 

Magadan, Sakhalin, Yukutiya; Eastern 

Asian Russia: Altay, West Siberia; 

European Russia: Irkutsk, Khabarovsk), 

Saint Pierre and Miquelon, United 

States (Alaska, California, Colorado, 

Idaho, Maine, Montana, New Hampshire, New York, Oregon, South Dakota, 

Utah, Washington, Wyoming)

Refs: 5, 44, 49, 55, 74, 81, 95, 133, 

143, 182, 194, 208, 217, 221, 222, 

223, 224, 225, 233

Assessor: Stritch, L.

Betula gmelinii Bunge

Taxonomic note: B. apoiensis, a species 

previously listed as Vulnerable in the 

1997 IUCN Red List of Threatened 

Plants (ref 236), is a probable local 

variant of B. gmelinii

China (N Heilongkiang, N Liaoning, Nei 

Mongol), Democratic People’s Republic 

of Korea, Japan (Hokkaido: Mt Apoi), N

Mongolia, Republic of Korea, Russian 

Federation (Central Asian Russia: 

Buryatiya, Chita, Krasnoyarsk, Yakutiya; 

Eastern Asian Russia: West Siberia; 

European Russia: Irkutsk)

Refs: 5, 42, 74, 99, 133, 222, 236

Betula grossa Sieb. & Zucc.

Japan (Honshu, Kyushu, Shikoku)

This species has a fairly small range, 

but it colonises easily following disturbance. It is therefore assessed as Least 

Concern, but would benefit from further 

field research to verify distribution and 

population status within its range. 

Refs: 5, 74, 133, 154, 208, 222

Betula humilis Schrank 

People’s Republic of Korea, Estonia, 

Germany, Kazakhstan, Latvia, Lithuania, 

Poland, Republic of Korea, Romania, 

Switzerland, Russian Federation 

(Central Asian Russia: Buryatiya, 

Krasnoyarsk; Eastern Asian Russia: 

West Siberia; European Russia: Central 

European Russia, East European Russia, Irkutsk, Kaliningrad, Khabarovsk, 

South European Russia, Northwest 

European Russia), Mongolia, Ukraine

This species has a wide but patchy 

distribution and has a reducing 

population across its range, which is 

likely to continue to decline if additional 

conservation measures are not put in 

place. It is now rare in Western Europe, 

has only a few locations reported in 

Germany, is scarce in Poland where 

it appears to be absent from formerly 

recorded sites, and is thought to be 

extinct in the Czech Republic where it 

has not been seen for at least 50 years. 

Populations are reported to be rare 

in Austria, Vulnerable in Romania and 

Critically Endangered in Switzerland. 

This species has declined over past 

centuries, primarily due to the advance 

of cultivation and the drainage of bogs. 

The threats facing this species are not 

likely to cease, therefore depending on 

current area of occupancy, this species 

could qualify as Vulnerable under 

criterion A due to its reduced population. However, due to a lack of data on 

population reductions, it is currently not 

possible to specify a threat category 

or Near Threatened category. Further 

study is needed to better quantify the 

population size reduction.

Refs: 5, 11, 22, 40, 42, 71, 74, 78, 99, 

109, 116, 124, 131, 133, 138, 149, 

208, 216, 222, 244, 251

Betula insignis Franch.

Betula insignis subsp. insignis

China (Chongqing, Fujian?, Guangdong?, Guangxi?, Guizhou, Hunnan, W 

Hubei, Jiangxi?, Sichuan, Yunnan)

This species and subspecies are 

common and widespread in central 

China. They have no known threats. 

The species is assessed as Least 

Concern on the Chinese Red List. (The 

species and type subspecies share the 

same distribution).

Refs: 5, 42, 74, 75, 77, 99, 133, 208, 

222

Betula insignis subsp. fansipanensis

Ashburner & McAll.

DD

Taxonomic note: Described for the first 

time by Ashburner and McAllister, 2013

China (Yunnan), Vietnam

This little known subspecies occurs 

on mountain ridges on limestone, in 

southwest Yunnan and Fan-Si-Pan 

in Vietnam. As this taxon is recently 

described, further field research is 

required to enable a full conservation 

assessment to be undertaken. It is 

assessed here as Data Deficient. 

Refs: 5

Betula lenta L.

Betula humilis

Austria, Belarus, China (Xinjiang: Altay 

Shan), Czech Republic, Democratic 

Betula lenta f. uber

Taxonomic note: B. uber, previously 

reported as threatened, is thought to be 

a form of B. lenta because leaf shape is 

the only consistent differential character. 

Assessments for B. lenta f. lenta and 

B. lenta f. uber are included here. Their 

range information is incorporated into 

the species-level assessment. See case 

study 1 for more information on B. lenta 

forma uber.
The Red List of Betulaceae

44

Japan (Honshu, Hokkaido), Russian 

Federation (Central Asian Russia: Kurile 

Islands)

Refs: 5, 74, 133, 136, 154, 177, 208, 

222

Betula michauxii Spach

Canada (Labrador, New Brunswick, 

Newfoundland, Nova Scotia, Québec), 

Saint Pierre and Miquelon

Refs: 5, 44, 74, 133, 208, 222, 224, 

233

Assessor: Stritch, L.

Mississippi, Missouri, New Hampshire?, 

New Jersey, New York, North Carolina, 

Ohio, Oklahoma, Pennsylvania, South 

Carolina, Tennessee, Texas, Vermont, 

Virginia, West Virginia, Wisconsin)

This species is ranked G5 (Secure) on 

NatureServe.

Refs: 5, 16, 27, 38, 43, 44, 55, 74, 90, 

119, 133, 143, 172, 202, 208, 222, 

223, 224, 232

Assessor: Stritch, L.

Betula occidentalis Hook.

Canada (Alberta, British Columbia, 

Manitoba, Northwest Territories, 

Nunavut?, Ontario, Saskatchewan, 

Yukon), United States (Alaska, Arizona, 

California, Colorado, Idaho, Montana, 

Nebraska, Nevada, New Mexico, North 

Dakota, Oregon, South Dakota, Utah, 

Washington, Wyoming)

This species is ranked G5 (Secure) on 

NatureServe.

Refs: 5, 34, 35, 44, 74, 90, 118, 133, 

143, 182, 208, 217, 218, 221, 222, 

223, 224, 225, 233, 239

Assessor: Stritch, L.

Betula papyrifera Marshall

Taxonomic note: B. kenaica is said to 

differ from B. papyrifera primarily in its 

smaller stature and in its smaller, blunter-tipped, more coarsely and regularly 

serrate leaves. It is best considered a 

westward extension of B. papyrifera into 

southern Alaska, perhaps affected by 

introgression from B. pendula subsp. 

mandshurica.

Canada (Alberta, British Columbia, 

Labrador, Manitoba, New Brunswick, 

Newfoundland, Northwest Territories, 

Nova Scotia, Ontario, Prince Edward 

Island, Quebec, Saskatchewan, Yukon), 

Saint Pierre and Miquelon, United 

States (Alaska, Colorado, Connecticut, 

Idaho, Illinois, Indiana, Iowa, Maine, 

Massachusetts, Michigan, Minnesota, 

Montana, Nebraska, New Hampshire, 

New Jersey, New York, North Dakota, 

Ohio?, Oregon, Pennsylvania, Rhode 

Island, South Dakota, Vermont, 

Washington, West Virginia?, Wisconsin, 

Wyoming)

This species is ranked G5 (Secure) on 

NatureServe.

Refs: 5, 16, 44, 50, 74, 90, 95, 119, 

133, 143, 172, 202, 208, 221, 222, 

223, 224, 225, 233

Assessor: Stritch, L.

Betula microphylla Bunge

Taxonomic note: Betula halophila is a 

probable synonym of B. microphylla. The 

status of B. halophila is uncertain–this 

species previously listed as Extinct in 

the 1997 IUCN Red List of Threatened 

Plants. Although its unique habitat for a 

birch suggests that it may be genetically 

distinct from any other birch, it is not 

easily distinguishable morphologically. 

China (Xinjiang: Altay Shan, Hami Xian), 

Kazakhstan, Kyrgyzstan?, Mongolia, 

Russian Federation (Altay, Buryatiya, 

Tuva), Uzbekistan

Refs: 5, 42, 74, 99, 133, 208, 236

Betula nana L.

Austria, Belarus, Canada (Nunavut)?, 

Czech Republic, Estonia, Finland, 

France, Germany, Greenland, Iceland, 

Italy, Latvia, Lithuania, Norway, Poland, 

Romania, Russian Federation (Central 

Asian Russia: Krasnoyarsk; Eastern 

Asian Russia: West Siberia; European 

Russia: Central European Russia, 

East European Russia, Irkutsk, North 

European Russia), Slovakia, Svalbard 

and Jan Mayen, Sweden, Switzerland, 

United Kingdom (Great Britain)

This species is ranked G5 (Secure) on 

NatureServe.

Refs: 4, 5, 19, 31, 40, 44, 53, 74, 78, 

109, 116, 131, 133, 138, 142, 143, 

149, 156, 208, 215, 222, 224, 233, 244

Assessor: Stritch, L.

Betula nigra L.

Betula maximowicziana

Betula nigra

Canada (Ontario), United States 

(Alabama, Connecticut, Georgia, 

Kentucky, Maine, Maryland, Massachusetts, Mississippi, New Hampshire, New 

Jersey, New York, North Carolina, Ohio, 

Pennsylvania, Rhode Island, South 

Carolina, Tennessee, Vermont, Virginia, 

West Virginia). 

This species is ranked G5 (Secure) on 

NatureServe (ref 143).

Refs: 5, 16, 44, 74, 77, 90, 119, 133, 

143, 172, 208, 224, 228, 233

Assessor: Stritch, L.

Betula luminifera H.J.P.Winkl. 

China (Anhui, Fujian, Gansu, N Guangdong, Guangxi, Guizhou, Henan, Hubei, 

Hunan, Jiangsu, Jiangxi, Shaanxi, 

Sichuan, Yunnan, Zhejiang)

This species is common and widespread across its range, with no known 

threats. This species is assessed as 

Least Concern on the Chinese Red List.

Refs: 5, 42, 74, 75, 99, 133, 208, 222

Betula maximowicziana Regel 

United States (Alabama, Arkansas, 

Connecticut, Delaware, District of Columbia, Florida, Georgia, Illinois, Indiana, 

Iowa, Kansas, Kentucky, Louisiana, 

Maryland, Massachusetts, Minnesota, 
The Red List of Betulaceae

45

Betula pendula Roth

Taxonomic notes: (1) Trees from the 

extremes of the distribution in Europe 

(B. pendula), north-east Asia and 

Japan and western North America (B. 

platyphylla, B. mandshurica) and SW 

China and Tibet (B. szechuanica) do 

look different and can be distinguished 

from one another. However, when the 

whole continuous geographical range 

of diploid silver birches is considered, 

all those named as species intergrade 

in geographically intervening areas. 

It is thought to be best divided into 

three subspecies, subsp. pendula in 

Europe and eastwards to central Asia, 

subsp. mandshurica in eastern Asia 

and western North America and subsp. 

szechuanica in western China from 

Qinghai and Gansu to Yunnan and 

southeast Xizang (2) B. platyphylla has 

been described as a separate species, 

representing birches from Mongolia 

east of the Altai and into western and 

north-eastern China but it is thought the 

two are synonymous (3) B. oycoviensis

previously listed as threatened is a form 

of B. pendula (4) B. pendula subsp. 

font-queri and B. pendula subsp. 

parvibracteata, previously listed as 

threatened are thought to be only minor 

variants of B. pendula (5) B. szaferi, 

described previously as extinct in the 

wild, is now considered a weak growing 

and heavily fruiting form of B. pendula, 

due to the presence of a mutant gene

Albania, Armenia, Austria, Azerbaijan?, Belarus, Belgium, Bosnia 

and Herzegovina, Bulgaria, Canada 

(Alberta, British Colombia, Manitoba, 

Northwest Territories, Nunavut, Ontario, 

Saskatchewan, Yukon), China (Gansu, 

Heilongjiang, Jilin, Liaoning, Qinghai, Sichuan, Xinjiang, SE Xizang, N Yunnan), 

Croatia, Czech Republic, Denmark,

Estonia, Finland, France (inc. Corsica), 

Georgia, Germany, Greece, Hungary,

Iraq, Islamic Republic of Iran, Italy (inc. 

Sicily), Japan, Kazakhstan, Kyrgyzstan?, Latvia, Liechtenstein, Lithuania, 

Luxembourg, Mongolia, Montenegro, 

Morocco, Netherlands, Norway, Poland,

Romania, Russian Federation (Central 

Asian Russia: Amur, Chita, Buryatiya, 

Krasnoyarsk, Magadan, Tuva, Yakutiya;

Eastern Asian Russia: Altay, West Siberia; European Russia: Central European 

Russia, Chechnya, Dagestan, East 

European Russia, Ingushetiya, Irkutsk,

Kabardino-Balkariya, Karachaevo-Cherkessiya, Krasnodar, North European 

Russia, Northwest European Russia,

Severo-Osetiya, South European 

Russia, Stavropol), Serbia (inc. Kosovo),

Slovakia, Slovenia, Spain, Sweden,

Switzerland, The Former Yugoslav 

Republic of Macedonia, Turkey in Asia, 

Ukraine (inc. Krym), United Kingdom 

(Great Britain, Northern Ireland), United 

States (Alaska), Uzbekistan

Refs: 4, 5, 12, 15, 19, 23, 30, 40, 61, 

71, 74, 99, 102, 110, 116, 131, 133, 

138, 146, 149, 175, 177, 189, 203, 

204, 208, 213, 215, 222, 229, 249

Betula pendula subsp. pendula

Albania, Armenia, Austria, Azerbaijan?, 

Belarus, Belgium, Bosnia and Herzegovina, Bulgaria, Croatia, Czech Republic, Denmark, Estonia, Finland, France 

(inc. Corsica), Georgia, Germany, 

Greece, Hungary, Iraq, Islamic Republic 

of Iran, Italy (inc. Sicily), Kazakhstan, 

Kyrgyzstan?, Latvia, Lithuania, 

Luxembourg, Mongolia, Montenegro, 

Morocco, Netherlands, Norway, Poland, 

Romania, Russian Federation (Central 

Asian Russia: Chita, Buryatiya, Krasnoyarsk, Tuva; Eastern Asian Russia: 

Altay, West Siberia; European Russia: 

Central European Russia, Chechnya, 

Dagestan, East European Russia, Ingushetiya, Irkutsk, Kabardino-Balkariya, 

Karachaevo-Cherkessiya, Krasnodar, 

North European Russia, Northwest 

European Russia, Severo-Osetiya, 

South European Russia, Stavropol), 

Serbia (inc. Kosovo), Slovakia, Slovenia, 

Spain, Sweden, Switzerland, The 

Former Yugoslav Republic of Macedonia, Turkey in Asia, Ukraine (inc. Krym), 

United Kingdom (Great Britain, Northern 

Ireland), Uzbekistan

Refs: 4, 5, 12, 15, 19, 23, 30, 40, 61, 

71, 74, 99, 102, 110, 116, 131, 133, 

138, 146, 149, 175, 177, 189, 203, 

204, 208, 213, 215, 222, 229, 249

Betula pendula subsp. mandshurica 

(Regel) Ashburner & McAll.

Taxonomic note: a newly described 

combination by Ashburner & McAllister, 

2013 

Canada (Alberta, British Colombia, Manitoba, Northwest Territories, Nunavut, 

Ontario, Saskatchewan, Yukon), China 

(Heilongjiang, Liaoning, Jilin), Japan, 

Russian Federation (Russian Federation 

(Central Asian Russia: Buryatiya, Chita, 

Krasnoyarsk, Yakutiya; Eastern Asian 

Russia: West Siberia; European Russia: 

Irkutsk), United States (Alaska) 

Refs: 5, 44, 177, 221, 223, 224, 225

Assessor: Stritch, L. 

Betula pendula subsp. szechuanica

(C.K.Scheid.) Ashburner & McAll.

DD

Taxonomic note: a newly described combination by Ashburner & McAllister, 2013

China (Gansu, Qinghai, Sichuan, SE 

Xizang, N Yunnan)

This little known subspecies occurs as 

a tree to 10 m with a spreading habit, 

occurring in woodland and on open hillsides. This taxon is cultivated for ornamental purposes. This taxon is reported 

to have a fairly wide distribution, occurring across five states of China. However, 

it is recently described and no population information or detailed distribution 

information is available for this species. 

Additional field research is needed to 

determine distribution and population 

status to enable a full conservation 

assessment to be undertaken. It is 

assessed here as Data Deficient. 

Refs: 5, 177

Betula populifolia Marshall

Canada (New Brunswick, Nova Scotia, 

Ontario, Prince Edward Island, Quebec), 

United States (Connecticut, Delaware, 

Illinois, Indiana, Maine, Maryland, 

Massachusetts, New Hampshire, New 

Jersey, New York, North Carolina, Ohio, 

Pennsylvania, Rhode Island, Vermont, 

Virginia, West Virginia)

This species is ranked G5 (Secure) on 

NatureServe (ref 143).

Refs: 5, 44, 55, 74, 81, 90, 133, 135, 

143, 169, 172, 208, 217, 221, 222, 

223, 224, 233

Assessor: Stritch, L.

Betula potaninii Batalin

Taxonomic notes: (1) B. delavayi, 

B. bomiensis, B. calcicola and B. potaninii

taxa are very confused. However they 

are separable by their visible morphological characters, ploidy and geographical distribution. (2) B. trichogemma 

seems to be no more than a minor 

variant of B. potaninii. (3) B. jiulungensis

may be a tree form of B. potaninii or 

perhaps a distinct species
The Red List of Betulaceae

46

China (SE Gansu, Shaanxi, N and W 

Sichuan)

This species has no known threats and 

is assessed as Least Concern on the 

Chinese Red List

Refs: 5, 42, 74, 75, 99, 133, 208, 222

Betula pubescens Ehrh.

Taxonomic note: (1) Although there is 

great variation in habit and stature in 

trees of this species associated with 

different habitats there are no clear 

boundaries between the different forms. 

The most useful taxonomic treatment is 

to give names to the most distinct, but 

only at the varietal level. Therefore var. 

pubescens for the tall central European 

and southern British and Scandinavian 

populations, var. pumila for northern 

populations, which are probably derived 

from var. pubescens through adaptive 

selection and introgression from B. nana, 

var. fragrans for aromatic, small leaved 

trees from northwest Britain, and var. 

litwinowii for Anatolian and Caucasian 

populations which are probably largely 

the result of introgression from B. 

pendula 

Armenia, Austria, Azerbaijan, Belarus, 

Belgium, Bosnia and Herzegovina, 

Canada (Newfoundland), Croatia, Czech 

Republic, Denmark, Estonia, Finland, 

France, Georgia, Germany, Greenland, 

Hungary, Iceland, Italy, Latvia, Liechtenstein, Lithuania, Luxembourg, Montenegro, Netherlands, Norway, Poland, 

Romania, Russian Federation (Central 

Asian Russia: Buryatiya, Krasnoyarsk, 

Yakutiya; Eastern Asian Russia: Altay, 

West Siberia; European Russia: Central 

European Russia, Chechnya, Dagestan, 

East European Russia, Ingushetiya, Irkutsk, Kabardino-Balkariya, KarachaevoCherkessiya, Khabarovsk, Krasnodar, 

North European Russia, Northwest European Russia, Severo-Osetiya, South 

European Russia, Stavropol), Serbia 

(inc. Kosovo), Slovenia, Spain, Sweden, 

Switzerland, The Former Yugoslav 

Republic of Macedonia, Turkey in Asia, 

Turkey in Europe, Ukraine, United Kingdom (Great Britain, Northern Ireland)

Refs: 4, 5, 8, 12, 19, 23, 40, 44, 69, 71, 

74, 111, 116, 131, 133, 138, 146, 148, 

149, 153, 189, 192, 199, 204, 208, 

212, 213, 215, 222, 224, 233, 249

Betula pubescens var. pubescens

Armenia, Austria, Azerbaijan, Belarus, 

Belgium, Bosnia and Herzegovina, 

Croatia, Czech Republic, Denmark, 

Estonia, France, Georgia, Germany, 

Hungary, Italy, Latvia, Liechtenstein, 

Lithuania, Luxembourg, Montenegro, 

Netherlands, Poland, Romania, Russian 

Federation (Central Asian Russia: Buryatiya, Krasnoyarsk, Yakutiya; Eastern 

Asian Russia: Altay, West Siberia; 

European Russia: Central European 

Russia, Chechnya, Dagestan, East 

European Russia, Ingushetiya, Irkutsk, 

Kabardino-Balkariya, Karachaevo-Cherkessiya, Khabarovsk, Krasnodar, North 

European Russia, Northwest European 

Russia, Severo-Osetiya, South European Russia, Stavropol), Serbia (inc. 

Kosovo), Slovenia, Spain, Switzerland, 

The Former Yugoslav Republic of 

Macedonia, Turkey in Asia, Turkey in 

Europe, Ukraine, United Kingdom (Great 

Britain, Northern Ireland)

Refs: 4, 5, 8, 12, 19, 23, 40, 44, 69, 71, 

74, 111, 116, 131, 133, 138, 146, 148, 

149, 153, 189, 199, 204, 213, 215, 

222, 224, 233, 249

Betula pubescens var. fragrans

Ashburner & McAll.

DD

Taxonomic note: this is described as a 

new variety by Ashburner & McAllister, 

2013

United Kingdom (Great Britain: Northumberland, Lake Bala)

Small trees to about 5 m with twisted 

trunks. This taxon can be found on 

steep hillsides and rocky streambanks 

in the mountains and throughout the 

Scottish Highlands at all altitudes. This 

is a new variety described by Ashburner 

and McAllister (2013). Little information 

is available about this taxon. 

Refs: 5

Betula pubescens var. golitsinii

(V.N.Vassil.) Tzvelev

DD

South European Russia

This taxon is not listed by Ashburner 

and McAllister but are recognised 

by the World Checklist of Selected 

Plant Families. Due to the taxonomic 

uncertainty and very little information 

available on distribution and population 

status, it is assessed as Data Deficient 

and in need of further study.

Refs: 5, 74

Betula pubescens var. litwinowii 

(Doluch.) Ashburner & McAll.

DD

Taxonomic notes: (1) A newly described 

combination by Ashburner and McAllister, 2013 (2) B. litwinowii is hardly 

distinguishable from B. pubescens var. 

litwinowii of the Swiss Jura or the Pyrenees (3) B. recurvata differs mainly in its 

larger leaves and absence of resin glands 

and is probably a local variant (4) The 

recently described B. browicziana, which 

was listed as Rare in the 1997 IUCN 

Red List of Threatened Plants (ref 236) 

and Endangered at a GTSG regional 

tree Red Listing workshop in Georgia in 

2005, is thought to be a local variant

Armenia, Azerbaijan, Georgia, Russian 

Federation (European Russia: Chechnya, 

Dagestan, Ingushetiya, KabardinoBalkariya, Karachaevo-Cherkessiya, 

Krasnodar, Severo-Osetiya, Stavropol), 

Turkey in Asia

At high elevations it has a multi-stemmed, 

crooked shape and is shorter in height. 

It is often found clinging to cliff sides. 

The status of this taxon remains 

uncertain. 

Refs: 5, 8, 192, 236, 256

Betula pubescens var. pumila (L.) 

Govaerts

DD

Canada (Newfoundland), Finland, 

Greenland, Iceland, Norway, Russian 

Federation (Eastern Asian Russia: Altay, 

West Siberia; North European Russia), 

Sweden

A dwarf shrub found in sheltered rocky 

valleys in the arctic, and on mountains 

further south. These populations are 

extensive and dominate the vegetation 

over large areas. The conservation 

status of this taxon remains uncertain. 

Refs: 5, 74, 133, 208, 212

Betula potaninii
The Red List of Betulaceae

47

Betula pumila L.

Canada (Alberta, British Columbia, 

Labrador, Manitoba, New Brunswick, 

Newfoundland, Northwest Territories, 

Nova Scotia, Ontario, Prince Edward 

Island, Québec, Saskatchewan, 

Yukon), Saint Pierre and Miquelon, 

United States (California, Colorado, 

Connecticut, Idaho, Illinois, Indiana, 

Iowa, Kansas, Maine, Massachusetts, 

Michigan, Minnesota, Montana, Nebraska, New Hampshire, New Jersey, 

New York, North Dakota, Ohio, Oregon, 

South Dakota, Vermont, Washington, 

Wisconsin, Wyoming)

This species is ranked G5 (Secure) on 

NatureServe (ref 143).

Refs: 5, 44, 74, 133, 143, 208, 221, 

222, 224, 225, 233

Assessor: Stritch, L.

Betula raddeana Trautv.

Armenia? Azerbaijan, Georgia, Russian 

Federation (Dagestan, KaracheyevoCherkessiya)

This species was assessed as Near 

Threatened in the World List of Threatened Trees. However a more recent 

assessment led by the IUCN, Missouri 

Botanical Garden and botanists from 

five countries situated in the Caucasus 

region, has reassessed this species as 

Least Concern due to its wide distribution 

on the eastern Greater Caucasus, presumed large population and because it 

is unlikely to be declining fast enough to 

qualify for listing in a threatened category. 

However, population monitoring is needed, 

taking into account forest clear-cutting 

and negative effects of traditional land 

use (incl. grazing and cattle camping in 

subalpine forests). The effects of global 

climate change on this species should 

be studied, but it is predicted to ascend 

to higher altitudes. 

Refs: 5, 8, 9, 74, 110, 133, 192, 208, 

222

Assessor: IUCN/SSC Caucasus Plant 

Red List Authority

Betula utilis D.Don

Taxonomic notes: (1) B. utilis, B. jacquemontii and B. albosinensis, are clearly 

closely related, and have been recognised in the past as separate species, 

subspecies or varieties. All are tetraploid 

and, although the extremes are very 

different, it is often difficult to distinguish 

between them. They are here treated as 

subspecies of B. utilis: B. utilis subsp. 

utilis, B. utilis subsp. jacquemontii, B. 

utilis subsp. albosinensis (2) B. jinpingensis is doubtfully distinct from B. utilis

Afghanistan, Bhutan, China (Gansu, 

Hebei, Henan, Hubei, Ningxia, Qinghai, 

Shaanxi, Shanxi, W Sichuan, E and S 

Xizang, NW Yunnan), India (Arunachal 

Pradesh, Darjiling, Himachal Pradesh, 

Jammu-Kashmir, Sikkim, Uttaranchal), 

Kazakhstan, Kyrgyzstan, Nepal, Pakistan, 

Tajikistan, Uzbekistan

Refs: 2, 5, 9, 41, 42, 45, 68, 74, 99, 

107, 122, 125, 133, 177, 208, 219, 222

Betula utilis subsp. utilis

Afghanistan, India (Jammu-Kashmir), 

Kazakhstan, Kyrgyzstan, Pakistan, 

Tajikistan, Uzbekistan

Refs: 5, 74, 133, 208

Betula utilis subsp. albosinensis

(Burkill) Ashburner & McAll.

DD

China (Gansu, Hebei, Henan, Hubei, 

Ningxia, Shaanxi, Shanxi, Sichuan)

A tree to 35 m it forms a component of 

cool temperate mixed or mainly conifer 

forest. It is cultivated for ornamental 

use. The wood is hard, dense and 

rather brittle, being used for many 

purposes. There is little information 

available about this taxon. Further 

research is required. It is assessed here 

as Data Deficient.

Refs: 5, 177

Betula utilis subsp. jacquemontii

Betula utilis subsp. utilis

Bhutan, China (Sichuan, Xizang, 

Yunnan), India (Arunachal Pradesh, 

Darjiling, Sikkim), Nepal

Refs: 2, 5, 9, 41, 42, 45, 68, 74, 99, 

107, 122, 125, 133, 177, 208, 219, 222

Betula utilis subsp. occidentalis Kitam

Betula utilis subsp. occidentalis

Betula utilis subsp. jacquemontii

(Spach) Ashburner & McAll.

DD

India (Himanchal Pradesh, JammuKashmir, Uttaranchal), Nepal

A small tree to 15 m, this taxon is found 

in forests, stony river beds, screes and 

rocky places in the mountains. Older 

trees develop thick plates of bark and 

form gnarled trees on the mountains. 

It is cultivated as an ornamental, this 

taxon has long been a favourite in 

gardens and arboreta. The timber is 

used for firewood, and the bark stripped 

for roofing. Further population information is required to ensure exploitation is 

not causing a population decline. It is 

assessed here as Data Deficient.

Refs: 5, 74, 133, 208
The Red List of Betulaceae

48

Carpinus betulus L.

Carpinus cordata var. cordata

China (SE Gansu, Hebei, Heilongjiang, 

Jilin, Liaoning, Shaanxi, Shandong: 

Kunyu Shan, Shanxi), Democratic 

People’s Republic of Korea, Japan 

(Hokkaido, Honshu, Kyushu, Shikoku), 

Republic of Korea, Russian Federation 

(Central Asian Russia: Primoryi)

Refs: 42, 74, 99, 133, 208

Carpinus cordata var. chinensis

Franch.

Albania, Armenia, Austria, Azerbaijan, 

Belarus, Belgium, Bosnia and 

Herzegovina, Bulgaria, Croatia, Czech 

Republic, Denmark, Estonia, France, 

Georgia, Germany, Greece, Hungary, 

Islamic Republic of Iran, Italy, Latvia, 

Liechtenstein, Lithuania, Luxembourg, 

Moldova, Montenegro, Netherlands, 

Poland, Romania, Russian Federation 

(European Russia: Central European 

Russia, Chechnya, Dagestan, Ingushetiya, Kabardino-Balkariya, Kaliningrad, 

Karacheyevo-Cherkessiya, Krasnodar, 

Severo-Osetiya, South European 

Russia, Stavropol), Serbia, Slovakia, 

Slovenia, Spain, Sweden, Switzerland, 

The Former Yugoslav Republic of 

Macedonia, Turkey in Asia, Turkey in 

Europe, Ukraine, United Kingdom (Great 

Britain)

Refs: 15, 19, 22, 23, 30, 71, 74, 116, 

131, 133, 137, 138, 146, 149, 176, 

189, 204, 208, 222, 224, 247, 249

Carpinus caroliniana Walter

Taxonomic note: there is some confusion 

in the naming of this species. This species 

has been recorded as Near Threatened 

in the Mexican cloud forests but it is now 

recognised that C. tropicalis is the accepted name of this tree species as it 

occurs in Mexico and Central America. 

The range of C. caroliniana is now 

delimited to North America. The ranges 

of the two subspecies overlap and 

hybrids with intermediate features are 

common. 

Canada (Ontario, Quebec), United States 

(Alabama, Arkansas, Connecticut, Delaware, District of Columbia, Florida, Georgia, Illinois, Indiana, Iowa, Kentucky, 

Louisiana, Maine, Maryland, Massachusetts, Michigan, Minnesota, Mississippi, 

Missouri, New Hampshire, New Jersey, 

New York, North Carolina, Ohio, Oklahoma, Pennsylvania, Rhode Island, South 

Carolina, Tennessee, Texas, Vermont, 

Virginia, West Virginia, Wisconsin)

Carpinus betulus

Carpinus cordata

Carpinus cordata var. chinensis

This species is ranked G5 (Secure) on 

NatureServe.

Refs: 16, 29, 43, 44, 59, 66, 73, 74, 77, 

81, 90, 133, 135, 136, 143, 172, 200, 

202, 208, 217, 221, 222, 223, 224, 

225, 233

Carpinus caroliniana subsp. caroliniana

United States (Alabama, Arkansas, 

Delaware, Florida, Georgia, Illinois, 

Iowa?, Kentucky, Louisiana, Maryland, 

Mississippi, Missouri, New Jersey?, 

North Carolina, Oklahoma, South 

Carolina, Tennessee, Texas, Virginia)

This species is ranked G5T4T5 (Apparently Secure/Secure) on NatureServe 

(ref 143).

Refs: 16, 29, 44, 66, 73, 74, 77, 133, 

135, 143, 200, 217, 221, 224, 225

Carpinus caroliniana subsp. virginiana (Marshall) Furlow

Canada (Ontario, Quebec), United 

States (Alabama, Arkansas, Connecticut, Delaware, District of Columbia, 

Georgia, Illinois, Indiana, Iowa, Kentucky, Maine, Maryland, Massachusetts, 

Michigan, Minnesota, Mississippi, 

Missouri, New Hampshire, New Jersey, 

New York, North Carolina, Ohio, 

Oklahoma, Pennsylvania, Rhode Island, 

South Carolina, Tennessee, Vermont, 

Virginia, West Virginia, Wisconsin)

This species is ranked G5T5 (Secure) 

on NatureServe (ref 143).

Refs: 16, 29, 44, 74, 77, 81, 133, 135, 

143, 172, 202, 208, 217, 221, 224, 

225, 233

Assessor: Stritch, L.

Carpinus chuniana Hu

China (N Guangdong: Lechang Xian, 

Guizhou: Fanjing Shan, SE Hubei)

Assessed as Least Concern on the 

Chinese Red List. 

Refs: 42, 74, 99, 133, 208

Carpinus cordata Blume

China (Anhui, Gansu, Guizhou, Hebei, 

Hubei, Hunan, Jiangsu, Jiangxi, Liaoning, S Ningxia, Shaanxi, Shandong, 

Shanxi, Sichuan, Zhejiang), Democratic 

People’s of Korea, Japan (Hokkaido, 

Honshu, Kyushu, Shikoku), Republic 

of Korea, Russian Federation (Central 

Asian Russia: Primoryi)

Refs: 42, 74, 77, 99, 113, 133, 154, 

159, 208, 222

China (Anhui, SE Gansu, Guizhou, 

Hubei, Hunan, Jiangsu, Jiangxi, 

SW Shaanxi: Tabai Shan, Sichuan, 

Zhejiang), Japan (Honshu, Kyushu, 

Shikoku)?

Refs: 42, 74, 77, 99, 133, 208

Carpinus cordata var. mollis (Rehder) 

W.C.Cheng ex C.Chen

China (Gansu, S Ningxia, Shaanxi: Hua 

Shan, Sichuan)

Refs: 42, 74, 99, 133, 208

Carpinus fangiana Hu

China (N Guangxi, Guizhou, Sichuan, E 

Yunnan)

Assessed as Least Concern on the 

Chinese Red List.

Refs: 42, 74, 75, 77, 99, 133, 208
The Red List of Betulaceae

49

Carpinus kawakamii Hayata

China (Fuijian: Liancheng Xian)?, 

Province of China (Taiwan: Alishan)

Reported to be a common species 

with a large population and no known 

threats. Assessed as Least Concern on 

the Chinese Red List.

Refs: 42, 74, 77, 91, 94, 99, 120, 133, 

208, 222

Carpinus kawakamii var. kawakamii

DD

Province of China (Taiwan)

This taxon has a small reported 

distribution. There is limited information 

available about this taxon and further 

research is required. It is assessed here 

as Data Deficient. 

Refs: 42, 74, 77, 91, 94, 99, 133, 222

Carpinus kawakamii var. minutiserrata (Hayata) S.S.Ying

DD

Province of China (Taiwan)

Found in forests on mountain slopes 

at medium altitudes. This taxon has 

a small reported distribution. There is 

limited information available about this 

taxon and further research is required. It 

is assessed here as Data Deficient. 

Refs: 74, 120, 133, 208

Carpinus kweichowensis Hu

China (SW Guizhou: Zhenfeng Xian, SE 

Yunnan)

Assessed as Least Concern on the 

Chinese Red List.

Refs: 42, 74, 93, 99, 133, 208

Carpinus londoniana H.J.P.Winkl. 

Carpinus londoniana var. londoniana

China (S Anhui, Fujian, N Guangdong, 

Guangxi, SE Guizhou, Hainan, Hunan, 

Jiangxi, SC Sichuan, S Yunnan, 

Zhejiang), Lao People’s Democratic 

Republic, SE Myanmar, N Thailand, 

Vietnam

Refs: 42, 74, 77, 99, 106, 133, 208, 

210

Carpinus londoniana var. latifolius

P.C.Li

China (Zhejiang: Ningbo Xian)

Assessed as Least Concern on the 

Chinese Red List.

Refs: 42, 74, 99, 133

Carpinus londoniana var. lanceolata

(Hand.-Mazz.) P.C.Li

DD

China (Hainan)

Only found growing in subtropical 

forests on Hainan Island, population 

numbers are unknown. There is limited 

information available about this taxon 

and further research is required. It is 

assessed here as Data Deficient. 

Refs: 42, 74, 106, 133, 208, 210

Carpinus londoniana var. xiphobracteata P.C.Li

DD

China (Zhejiang: Yin Xian) 

Found growing in forests on moist 

mountain slopes at around 700 m ASL. 

There is limited information available 

about this taxon and further research 

is required. It is assessed here as Data 

Deficient.

Refs: 42, 74, 99, 133

Carpinus mollicoma Hu

China (Sichuan: Emi Shan, E Xizang: 

Bomi Zian, SE Yunnan: Malipo Xian)

Assessed as Least Concern on the 

Chinese Red List.

Refs: 42, 74, 99, 133, 208

Carpinus monbeigiana Hand.-Mazz.

China (Xizang, C and NW Yunnan)

Assessed as Least Concern on the 

Chinese Red List.

Refs: 42, 74, 75, 77, 99, 133, 208

Carpinus orientalis Mill.

Carpinus orientalis subsp. orientalis

Albania, Armenia, Azerbaijan, Bosnia and 

Herzegovina, Bulgaria, Croatia, Georgia, 

Greece, Hungary, Islamic Republic of Iran, 

Italy (inc. Sicilia), Lebanon?, Moldova, 

Montenegro, Romania, Russian Federation (European Russia: Chechnya, Dagestan, Ingushetiya, Kabardino-Balkariya, 

Karachaevo-Cherkessiya, Krasnodar, 

Severo-Osetiya, Stavropol), Serbia, 

Slovenia, Syrian Arab Republic?, The 

Former Yugoslav Republic of Macedonia, 

Turkey in Asia, Turkey in Europe, Ukraine 

(Krym) (The species and type subspecies 

share the same distribution).

Refs: 15, 30, 74, 110, 133, 136, 170, 

192, 203, 204, 208, 222, 249

Carpinus orientalis subsp. macrocarpa (Willk.) Browicz

DD

Islamic Republic of Iran

Often found in transition forests including deciduous temperate mixed forest 

and scrub at high altitudes. Further field 

Carpinus fargesiana H.J.P.Winkl.

Carpinus fargesiana var. fargesiana

China (S Gansu, W Henan, W Hubei, S 

Shaanxi, Sichuan)

Assessed as Least Concern on the 

Chinese Red List.

Refs: 42, 74, 77, 99, 133, 208, 222

Carpinus fargesiana var. hwai (Hu & 

W.C.Cheng) P.C.Li

China (W Hubei: Lichuan Xian, E Sichuan: 

Wan Xian)

Assessed as Least Concern on the 

Chinese Red List.

Refs: 42, 74, 99, 133, 208

Carpinus firmifolia (H.J.P.Winkl.) Hu

China (Guizhou: Guiyang Shi)

Assessed as Least Concern on the 

Chinese Red List.

Refs: 42, 74, 99, 133

Carpinus henryana (H.J.P.Winkl.) 

H.J.P.Winkl.

China (E Gansu, W Guizhou, Henan, W 

Hubei, S Shaanxi, E Sichuan, Yunnan)

Assessed as Least Concern on the 

Chinese Red List.

Refs: 42, 74, 75, 77, 99, 133, 208, 222

Carpinus henryana var. henryana

DD

China (Sichuan)

This taxon has a small reported distribution. There is limited information available about this taxon and further research 

is required. It is assessed here as Data 

Deficient. 

Refs: 74, 133, 208

Carpinus henryana var. oblongifolia

(Hu) Rushforth

DD

China (Hubei)

A tree to 18 m tall, found in subtropical 

forests. This taxon has a small reported 

distribution. There is limited information 

available about this taxon and further 

research is required. It is assessed here 

as Data Deficient. 

Refs: 74, 133, 208

Carpinus henryana var. simplicidentata

(Hu) Rushforth

DD

China (Hubei)

This taxon has a small reported distribution. There is limited information available 

about this taxon and further research 

is required. It is assessed here as Data 

Deficient. 

Refs: 74, 77, 133, 208
The Red List of Betulaceae

50

research is required to obtain enough 

information for an assessment to be 

performed.

Refs: 15, 74, 101, 133, 208

Carpinus polyneura Franch.

China (Fujian, N Guangdong, Guizhou, 

Hubei, Hunan, Jiangxi, Shaanxi, NE 

Sichuan: Chengkou Xian, Zhejiang)

Refs: 42, 74, 77, 99, 133, 208, 222

Carpinus polyneura var. polyneura 

DD

China (Hunan, Sichuan)

This taxon has a small reported 

distribution. There is limited information 

available about this taxon and further 

research is required. It is assessed here 

as Data Deficient.

Refs: 42, 74, 77, 99, 133, 208, 222

Carpinus polyneura var. sunpanensis

(K.C.Hsia) P.C.Li

DD

China (Sichuan)

Restricted to North Sichuan, this tree 

grows up to 10 m in height and is found 

in temperate broad-leaved forests. 

There is limited information available 

about this taxon and further research 

is required. It is assessed here as Data 

Deficient.

Refs: 74, 133, 208

Carpinus polyneura var. tsunyihensis

(Hu) P.C.Li

DD

China (Guizhou)

Found only in Guizhou. A tree to 7 m 

in height, it is found growing in mountainous mixed forest. There is limited 

information available about this taxon 

and further research is required. It is 

assessed here as Data Deficient.

Refs: 74, 133, 208

Carpinus pubescens Burkill

China (Guizhou, Hubei?, Shaanxi, 

Sichuan, Yunnan: Mile Xian), N Vietnam

Assessed as Least Concern on the 

Chinese Red List.

Refs: 42, 74, 75, 77, 99, 133, 208

Carpinus rankanensis Hayata

Taxonomic note: The two varieties 

(C. rankanensis var. rankanensis and 

C. rankanensis var. matsudae) are not 

recognised in the most recent taxonomic treatment.

Province of China (Taiwan)

Reported to be common across its 

range, with a large population and no 

known threats. The two varieties are

assessed as Least Concern on the 

Chinese Red List.

Refs: 42, 74, 77, 91, 94, 96, 99, 120, 

133, 208

Carpinus rupestris A.Camus

China (W Guangxi, SW Guizhou: Xingyi 

Xian, SE Yunnan)

Assessed as Least Concern on the 

Chinese Red List.

Refs: 42, 74, 99, 133, 208

Carpinus shensiensis Hu

China (S Gansu, S Shaanxi: Nanwutai)

Assessed as Least Concern on the 

Chinese Red List.

Refs: 42, 74, 77, 99, 133, 208

Carpinus tropicalis (Donn.Sm.) Lundell

Taxonomic note: There is some 

confusion over the naming of this 

species. It is sometimes referred to as 

C. caroliniana. 

El Salvador, Guatemala, Honduras, 

Mexico (Chiapas, Guerrero, Hidalgo, 

Jalisco, México State, Michoacán, 

Morelos, Nayarit, Neuvo León, Oaxaca, 

Puebla, San Luis Potosí, Sinaloa, 

Tamaulipas, Veracruz), Nicaragua

Refs: 10, 17, 29, 44, 65, 73, 74, 130, 

133, 145, 164, 187, 188, 208

Assessor: Stritch, L.

Carpinus tropicalis subsp. tropicalis

El Salvador, Guatemala, Honduras, 

Mexico (Chiapas, Guerrero, Hidalgo, 

Jalisco, Oaxaca, San Luis Potosí, 

Sinaloa, Veracruz), Nicaragua

Refs: 17, 66, 74, 133, 164

The parent species is reported to 

be Near Threatened within Mexico, 

however it is assessed globally as 

Least Concern as it is not considered 

threatened in other parts of its range. C. 

tropicalis subsp. tropicalis has a smaller 

distribution in Mexico and its distribution 

outside of Mexico aligns with the parent 

species. Neither are considered to meet 

thresholds to be considered threatened 

at present, but deforestation of cloud 

forest habitat poses a threat and therefore a reassessment is recommended 

in 10 years for both the parent species 

and C. tropicalis subsp. tropicalis.

Carpinus tropicalis subsp. mexicana

Furlow

DD

Mexico (Hidalgo, Jalisco, México State, 

Michoacán, Morelos, Nayarit, Neuvo 

León, Puebla, San Luis Potosí, Tamaulipas, Veracruz)

This subspecies is endemic to Mexico 

and occurs in the mountains and the 

trans-Mexican volcanic belt. It is found 

on moist slopes and canyons in cloud 

forest. The wood is collected for firewood and coal. This taxon is potentially 

threatened but further field research is 

needed to determine its conservation 

status. It is therefore assessed here as 

Data Deficient.

Refs: 17, 74, 133, 164

Carpinus tsaiana Hu

China (SW Guizhou, SE Yunnan: Pingbian Miaozu Sishixian)

Assessed as Least Concern on the 

Chinese Red List.

Refs: 42, 74, 99, 133, 208

Carpinus tschonoskii Maxim.

China (Anhui, Guangxi, Guizhou, W 

Henan, Hubei, Hunan, Jiangsu, Jiangxi, 

Sichuan, Yunnan, Zhejiang), Democratic 

People’s Republic of Korea, Japan 

(Honshu, Shikoku), Republic of Korea

Assessed as Least Concern on the 

Chinese Red List.

Refs: 42, 74, 99, 133, 136, 154, 159, 

174, 208, 222

Carpinus turczaninowii Hance

China (Beijing: Jinshan, S Gansu, 

Henan, Jiangsu, S Liaoning, Shaanxi, 

Shandong), Democratic People’s 

Republic of Korea, Japan (Honshu, 

Kyushu, Shikoku), Republic of Korea

Assessed as Least Concern on the 

Chinese Red List.

Refs: 42, 74, 77, 99, 133, 136, 154, 

159, 208, 222

Carpinus viminea Wall. ex Lindl. 

Bangladesh, Bhutan, China (Anhui, Fujian, 

N Guangdong, Guangxi, Guizhou, Hubei, 

Hunan, Jiangsu, Jiangxi, Sichuan, Xizang, 

Yunnan, Zhejiang), India (Arunachal 

Pradesh, Assam, Darjiling, Himachal 

Pradesh, Jammu-Kashmir, Manipur, 

Meghalaya, Mizoram, Nagaland, Sikkim, 

Tripura, Uttaranchal), Myanmar, Nepal, 

Thailand, Vietnam

Refs: 41, 42, 68, 74, 75, 77, 99, 133, 

208, 222, 234
The Red List of Betulaceae

51

Corylus americana Walter

Canada (Manitoba, Ontario, Quebec, 

Saskatchewan), United States 

(Alabama, Arkansas, Connecticut, 

Delaware, District of Columbia, Georgia, 

Illinois, Indiana, Iowa, Kansas, Kentucky, 

Louisiana, Maine, Maryland, Massachusetts, Michigan, Minnesota, Mississippi, 

Missouri, Nebraska, New Hampshire, 

New Jersey, New York, North Carolina, 

Ohio, Oklahoma, Pennsylvania, Rhode 

Island, South Carolina, South Dakota, 

Tennessee, Vermont, Virginia, West 

Virginia, Wisconsin)

This species is ranked G5 (Secure) on 

NatureServe (ref 143).

Refs: 43, 44, 74, 81, 133, 135, 143, 

172, 202, 208, 217, 222, 223, 224, 

233, 237

Assessor: Stritch, L.

Corylus avellana L.

Corylus avellana var. avellana

Albania, Armenia, Austria, Azerbaijan, 

Belarus, Belgium, Bosnia and 

Herzegovina, Bulgaria, Croatia, Czech 

Republic, Denmark, Estonia, Faroe 

Islands?, Finland, France (inc. Corsica), 

Georgia, Germany, Greece (inc. East 

Aegean Islands?, Kriti?), Hungary, 

Islamic Republic of Iran, Iraq?, Italy (inc. 

Sardegna, Sicilia), Latvia, Liechtenstein, 

Lithuania, Luxembourg, Moldova, 

Montenegro, Netherlands, Norway, 

Poland, Portugal, Romania, Russian 

Federation (European Russia: Central 

European Russia, Chechnya, Dagestan, 

East European Russia, Ingushetiya, 

Kabardino-Balkariya, Karachaevo-Cherkessiya, Krasnodar, North European 

Russia, Northwest European Russia, 

Severo-Osetiya, South European 

Russia, Stavropol), Serbia, Slovakia, 

Slovenia, Spain, Sweden, Switzerland, 

The Former Yugoslav Republic of 

Macedonia, Turkey in Asia, Ukraine 

(inc. Krym), United Kingdom (Great 

Britain, Northern Ireland) (The species 

and type subspecies share the same 

distribution).

Refs: 1, 4, 15, 19, 20, 23, 30, 36, 71, 

74, 85, 102, 110, 116, 131, 133, 136, 

138, 146, 149, 158, 170, 177, 189, 

203, 204, 208, 222, 249

Corylus avellana var. pontica (K.Koch) 

H.J.P.Winkl.

DD

Greece (East Aegean Islands?), 

Russian Federation (European Russia: 

Chechnya, Dagestan, Inguschetiya, 

Kabardino-Balkariya, Karachaevo-Cherkessiya, Krasnodar, Severo-Osetiya, 

Stavropol), Turkey in Asia. 

This lesser known variety is found 

growing in deciduous scrub and forest. 

It produces edible nuts which are often 

harvested from the wild and sold at 

local markets. There is little information 

available about this species. Over 

exploitation could present a threat to 

this species. It is assessed here as Data 

Deficient. 

Refs: 74, 85, 133, 158, 203, 208

Corylus chinensis Franch.

Stavropol), Serbia, The Former Yugoslav 

Republic of Macedonia, Turkey in Asia, 

Turkey in Europe

Refs: 15, 30, 45, 71, 74, 114, 133, 136, 

177, 197, 204, 208, 222, 249

Corylus cornuta Marshall

Canada (Alberta, British Columbia, 

Labrador, Manitoba, New Brunswick, 

Newfoundland, Nova Scotia, Ontario, 

Prince Edward Island, Quebec, Saskatchewan), Saint Pierre and Miquelon, 

United States (Alabama, California, Colorado, Connecticut, Delaware?, Georgia, 

Idaho, Illinois, Iowa, Kentucky, Maine, 

Maryland, Massachusetts, Michigan, 

Minnisota, Montana, New Hampshire, 

New Jersey, New York, North Carolina, 

North Dakota, Ohio, Oregon, Pennsylvania, Rhode Island, South Carolina, 

South Dakota, Tennessee, Vermont, 

Virginia, Washington, West Virginia, 

Wisonsin, Wyoming)

This species is ranked G5 (Secure) on 

NatureServe.

Refs: 44, 74, 81, 133, 135, 143, 172, 

182, 202, 208, 217, 222, 223, 224, 

233, 237

Corylus cornuta subsp. cornuta

Canada (Alberta, British Columbia, 

Labrador, Manitoba, New Brunswick, 

Newfoundland, Nova Scotia, Ontario, 

Prince Edward Island, Quebec, Saskatchewan), Saint Pierre and Miquelon, 

United States (Alabama, Colorado, Connecticut, Delaware?, Georgia, Idaho, 

Illinois, Iowa, Maine, Maryland, Massachusetts, Michigan, Minnesota, Montana, 

New Hampshire, New Jersey, New 

York, North Carolina, North Dakota, 

Ohio, Pennsylvania, Rhode Island, 

Corylus chinensis

China (Gansu, Guizhou, Henan?, Hubei, 

Hunan?, Shaanxi, SW Sichuan, Xizang, 

NW Yunnan)

This species was assessed as Endangered (EN) in the 1998 World List of 

Threatened Trees, but has a fairly wide 

distribution and is assessed as Least 

Concern on the Chinese Red List.

Declines have been witnessed due to 

deforestation, but the local assessment 

as Least Concern implies these threats 

are not large enough for this species to 

qualify in a threat category.

Refs: 42, 74, 99, 121, 133, 190, 208, 

222

Corylus colurna L.

Albania, Azerbaijan, Bosnia and Herzegovina, Bulgaria, Croatia?, Georgia, Greece, 

Islamic Republic of Iran, Montenegro, 

Romania, Russian Federation (European 

Russia: Chechnya, Dagestan, Inguschetiya, Kabardino-Balkariya, KarachaevoCherkessiya, Krasnodar, Severo-Osetiya, 

Corylus colurna at the Royal Botanic Gardens, 

Kew, Millennium Seed Bank
The Red List of Betulaceae

52

Corylus heterophylla Fisch. ex Trautv.

China (Anhui, E and S Gansu, Guizhou, 

Hebei, Heilongjiang, Henan, Hubei, 

Hunan, Jiangsu, Jiangxi, Jilin, Liaoning, 

E Nei Mongol, Ningxia, Shaanxi, Shandong, Shanxi, NE Sichuan, Zhejiang), 

Democratic People’s Republic of Korea, 

Japan (Hokkaido, Honshu, Kyushu), 

Republic of Korea, Russian Federation 

(Central Asian Russia: Amur, Chita, 

Khabarovsk, Primoryi), E Mongolia?

Refs: 42, 74, 75, 99, 113, 133, 154, 

159, 208, 222

Corylus heterophylla var. heterophylla

China (E Gansu, Hebei, Heilongjiang: 

Dailing, Daxinganling, Henan, 

Jilin: Changbai Shan, Liaoning, E Nei 

Mongol, Ningxia: Liupan Shan, Shanxi), 

Democratic People’s Republic of Korea, 

Japan (Hokkaido, Honshu, Kyushu), 

Republic of Korea, Russian Federation 

(Amur, Chita, Khabarovsk, Primoryi), 

E Mongolia?

Refs: 42, 74, 99, 133, 222

Corylus heterophylla var. sutchuenensis Franch.

China (Anhui, S Gansu, Guizhou, 

Henan, Hubei, Hunan, Jiangsu, Jiangxi, 

Shaanxi, Shandong, NE Sichuan: 

Chengkou Xian, Zhejiang)

Refs: 42, 74, 75, 99, 133, 208, 222

Corylus maxima Mill.

Croatia, Greece?, Serbia, Slovenia

Refs: 30, 74, 133, 136, 177, 208, 249

Corylus sieboldiana Blume

China (Gansu, Hebei, Heilongjiang, 

Henan, Jilin, Liaoning, Nei Mongol, 

Shaanxi, Sichuan), Democratic People’s 

Republic of Korea, Japan (Hokkaido, 

Honshu), Republic of Korea, Russian 

Federation (Central Asian Russia: Amur, 

Chita, Primoryi; European Russia: 

Khaborovsk)

Refs: 74, 113, 133, 154, 208, 222

Corylus sieboldiana var. sieboldiana 

DD

Democratic People’s Republic of 

Korea?, Japan (Hokkaido, Honshu, 

Kyushu, Shikoko) 

This taxon has a small reported 

distribution. There is limited information 

available about this taxon and further 

research is required. It is assessed here 

as Data Deficient. 

Refs: 74, 133, 159, 208, 222

Corylus sieboldiana var. mandshurica

(Maxim.) C.K.Schneid. 

South Carolina, South Dakota, Tennessee, Vermont, Virginia, West Virginia, 

Washington, Wisconsin, Wyoming)

This species is ranked G5T5 (Secure) 

on NatureServe.

Refs: 44, 74, 81, 133, 135, 143, 172, 

202, 224, 233, 237

Corylus cornuta subsp. californica 

(A.DC.) A.E.Murray

Taxonomic note: This subspecies is 

most often treated as a variety of the 

northern C. cornuta. The two taxa may 

not be very closely related, differing 

conspicuously in appearance, habitat, 

phytogeography and various other 

features. A thorough taxonomic study of 

this group should be undertaken. 

Canada (British Columbia), United 

States (California, Oregon, Washington)

This species is ranked G5T5 (Secure, 

inexact numeric rank) on NatureServe.

Refs: 44, 74, 133, 143, 182, 208, 217, 

223, 224, 233

Assessor: Stritch, L.

Corylus fargesii (Franch.) C.K.Schneid.

China (S Gansu, Guizhou, Henan, 

Hubei, Hunan, Jiangxi, S Ningxia, 

Shaanxi, NE Sichuan: Chengkou Xian)

Assessed as Least Concern on the 

Chinese Red List.

Refs: 42, 74, 77, 99, 133, 208, 222

Corylus ferox Wall.

Bhutan, China (SE Gansu, Guizhou, 

W Hubei, Ningxia, Shaanxi, E and 

SW Sichuan, Xizang, Yunnan), India 

(Arunachal Pradesh, Assam, Darjiling, 

Manipur, Meghalaya, Mizoram, Nagaland, Sikkim, Tripura), Myanmar, Nepal

Refs: 41, 42, 74, 75, 99, 125, 133, 151, 

208, 222

Corylus ferox var. ferox

Bhutan, China (Guizhou: Fanjiang Shan, 

SW Sichuan, NW and W Yunnan), India 

(Arunachal Pradesh, Assam, Darjiling, 

Manipur, Meghalaya, Mizoram, Nagaland, Sikkim, Tripura), Myanmar, Nepal

Refs: 42, 74, 99, 133, 208, 222

Corylus ferox var. tibetica (Batalin) 

Franch.

China (SE Gansu, Guizhou, W Hubei, 

Ningxia, Shaanxi, E Sichuan, Xizang, 

Yunnan)

Assessed as Least Concern on the 

Chinese Red List.

Refs: 42, 74, 75, 99, 133, 208, 222

Corylus sieboldiana var. mandshurica

Corylus sieboldiana var. mandshurica

China (E Gansu, Hebei, Heilongjiang, 

Henan, Jilin, Liaoning, Nei Mongol, 

Shaanxi, E and N Sichuan), Democratic 

People’s Republic of Korea, Japan 

(Hokkaido, Honshu), Republic of Korea, 

Russian Federation (Amur, Chita, 

Khabarovsk, Primoryi) 

This taxon has a wide distribution, however it would benefit from further research 

to verify population status. Its nuts are 

edible and therefore over-exploitation 

could be a risk.

Refs: 74, 133, 154, 159, 208, 222

Corylus wulingensis Q.X.Liu & 

C.M.Zhang

China (Hunan)

Assessed as Least Concern on the 

Chinese Red List.

Refs: 74, 99, 133, 208

Corylus yunnanensis (Franch.) 

A.Camus

China (W Guizhou, Hubei, SE and W 

Sichuan, W Yunnan: Dali Xian)

Assessed as Least Concern on the 

Chinese Red List.

Refs: 42, 56, 74, 75, 99, 107, 133, 208, 

222
The Red List of Betulaceae

53

Ostrya carpinifolia Scop.

Albania, Austria, Azerbaijan, Bosnia 

and Herzegovina, Bulgaria, Croatia, 

France (inc. Corsica), Georgia, 

Greece, Hungary?, Italy (inc. Sardegna, Sicilia), Lebanon, Montenegro, 

Russian Federation (European Russia: 

Chechnya, Dagestan, Ingushetiya, 

Kabardino-Balkariya, Karachaevo-Cherkessiya, Krasnodar, Severo-Osetiya, 

Stavropol), Serbia, Slovenia, Switzerland, Syrian Arab Republic, The Former 

Yugoslav Republic of Macedonia, 

Turkey in Asia, Turkey in Europe

Refs: 20, 30, 71, 74, 102, 110, 111, 

133, 170, 208, 222, 249

Ostrya japonica Sarg.

Tamaulipas, Veracruz), United States 

(Alabama, Arkansas, Connecticut, 

Delaware, District of Columbia, Florida, 

Georgia, Illinois, Indiana, Iowa, Kansas, 

Kentucky, Louisiana, Maine, Maryland, 

Massachusetts, Michigan, Minnesota, 

Mississippi, Missouri, Nebraska, New 

Hampshire, New Jersey, New York, 

North Carolina, North Dakota, Ohio, 

Oklahoma, Pennsylvania, Rhode Island, 

South Carolina, South Dakota, Tennessee, Texas, Vermont, Virginia, West 

Virginia, Wisconsin, Wyoming)

This species is ranked G5 (Secure) on 

NatureServe .

Refs: 10, 16, 29, 43, 44, 59, 73, 74, 

90, 130, 133, 135, 143, 145, 172, 187, 

188, 198, 202, 208, 217, 222, 223, 

224, 233, 237

Ostrya virginiana subsp. virginiana

Canada (Manitoba, New Brunswick, 

Nova Scotia, Ontario, Prince Edward 

Island, Quebec), United States 

(Alabama, Arkansas, Connecticut, 

Delaware, District of Columbia, Florida, 

Georgia, Illinois, Indiana, Iowa, Kansas, 

Kentucky, Louisiana, Maine, Maryland, 

Massachusetts, Michigan, Minnesota, 

Mississippi, Missouri, Nebraska, New 

Hampshire, New Jersey, New York, 

North Carolina, North Dakota, Ohio, 

Oklahoma, Pennsylvania, Rhode Island, 

South Carolina, South Dakota, Tennessee, Texas, Vermont, Virginia, West 

Virginia, Wisconsin, Wyoming)

This taxon is ranked G5T5 (Secure) on 

NatureServe. 

Refs: 16, 29, 73, 74, 133, 135, 143, 

172, 202, 217, 233, 237

Ostrya virginiana subsp. guatemalensis (H.J.P.Winkl.) A.E.Murray

El Salvador, Guatemala, Honduras, 

Mexico (Chiapas, Guerrero, Oaxaca, 

Veracruz)

Refs: 10, 29, 44, 73, 74, 130, 133, 145, 

187, 188, 198, 208

Assessor: Stritch, L.

Ostryopsis davidiana Decne.

China (Gansu, Hebei, Liaoning, Nei 

Mongol, Ningxia, Shaanxi, W Sichuan)

Refs: 42, 74, 99, 133, 168, 208, 222

Ostrya japonica

Ostrya carpinifolia

Ostrya knowltonii Sarg.

United States (Arizona, New Mexico, 

Texas, Utah)

This species is ranked G3G4 (Vulnerable/Apparently Secure) on NatureServe 

(ref 143).

Refs: 13, 14, 44, 74, 133, 143, 150, 

166, 208, 214, 217, 224, 240

Assessor: Stritch, L.

Ostrya multinervis Rehder

China (Guizhou, S Hunan: Xinning Xian 

and Junyan Shan, Jiangsu, SE Sichuan, 

Zhejiang)

Refs: 42, 74, 99, 133, 208

Ostrya trichocarpa D.Fang & 

Y.S.Wang

China (SW Guangxi)

Assessed as Least Concern on the 

Chinese Red List.

Refs: 42, 74, 99, 133, 208

Ostrya virginiana (Mill.) K.Koch

China (S Gansu, Hebei, Henan, Hubei, 

Shaanxi, W Sichuan), Democratic 

People’s Republic of Korea, Japan 

(Hokkaido, Honshu, Kyushu, Shikoku), 

Republic of Korea

Refs: 42, 74, 99, 133, 154, 159, 208, 

222, 224

Ostrya virginiana

Taxonomic note: There continues to 

be some debate on the acceptance of 

subspecific taxa of this species. It has 

been reported that Ostrya virginiana

is Near Threatened in The Red List of 

Mexican Cloud Forest Trees, however it 

is thought that this assessment refers to 

O. virginiana subsp. guatemalensis that 

occurs in cloud forests from southern 

Mexico into Guatemala, El Salvador and 

Honduras.

Canada (Manitoba, New Brunswick, 

Nova Scotia, S Ontario, S Quebec), 

El Salvador, Guatemala, Honduras, 

Mexico (Chiapas, Chihuahua?, Durango, Guerrero, Hidalgo, Jalisco, México 

State, Michoacán?, Nayarit, Neuvo 

León?, Oaxaca, Puebla, Queretaro?, 

San Luis Potosí?, Sinaloa, Sonora, 
The Red List of Betulaceae

54

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65

EXTINCT (EX)

A taxon is Extinct when there is no reasonable doubt that the

last individual has died. A taxon is presumed Extinct when

exhaustive surveys in known and/or expected habitat, at

appropriate times (diurnal, seasonal, annual), throughout its

historic range have failed to record an individual. Surveys

should be over a time-frame appropriate to the taxon’s life

cycle and life form.

EXTINCT IN THE WILD (EW)

A taxon is Extinct in the Wild when it is known only to survive

in cultivation, in captivity or as a naturalized population (or

populations) well outside the past range. A taxon is presumed

Extinct in the Wild when exhaustive surveys in known and/

or expected habitat, at appropriate times (diurnal, seasonal,

annual), through-out its historic range have failed to record an

individual. Surveys should be over a time-frame appropriate

to the taxon’s life cycle and life form.

CRITICALLY ENDANGERED (CR)

A taxon is Critically Endangered when the best available

evidence indicates that it meets any of the criteria A to E for

Critically En-dangered (see Section V), and it is therefore

considered to be facing an extremely high risk of extinction in

the wild.

ENDANGERED (EN)

A taxon is Endangered when the best available evidence indicates that it meets any of the criteria A to E for Endangered

(see Section V), and it is therefore considered to be facing a

very high risk of extinction in the wild.

VULNERABLE (VU)

A taxon is Vulnerable when the best available evidence

indicates that it meets any of the criteria A to E for Vulnerable

(see Section V), and it is therefore considered to be facing a

high risk of extinction in the wild.

NEAR THREATENED (NT)

A taxon is Near Threatened when it has been evaluated against

the criteria but does not qualify for Critically Endangered, Endangered or Vulnerable now, but is close to qualifying for or is

likely to qualify for a threatened category in the near future.

LEAST CONCERN (LC)

A taxon is Least Concern when it has been evaluated against

the criteria and does not qualify for Critically Endangered, Endangered, Vulnerable or Near Threatened. Widespread and

abundant taxa are included in this category.

DATA DEFICIENT (DD)

A taxon is Data Deficient when there is inadequate information to make a direct, or indirect, assessment of its risk of

extinction based on its distribution and/or population status.

A taxon in this category may be well studied, and its biology

well known, but appropriate data on abundance and/or distribution are lacking. Data Deficient is therefore not a category

of threat. Listing of taxa in this category indicates that more

information is required and acknowledges the possibility that

future research will show that threatened classification is

appropriate. It is important to make positive use of whatever

data are available. In many cases great care should be exercised in choosing between DD and a threatened status. If the

range of a taxon is suspected to be relatively circumscribed,

and a considerable period of time has elapsed since the last

record of the taxon, threatened status may well be justified.

NOT EVALUATED (NE)

A taxon is Not Evaluated when it is has not yet been evaluated 

against the criteria.

THE CRITERIA FOR CRITICALLY ENDANGERED, 

ENDANGERED AND VULNERABLE

CRITICALLY ENDANGERED (CR)

A taxon is Critically Endangered when the best available

evidence indicates that it meets any of the following criteria

(A to E), and it is therefore considered to be facing an extremely high risk of extinction in the wild:

A. Reduction in population size based on any of the following:

1. An observed, estimated, inferred or suspected population size reduction of ≥90% over the last 10 years or

three generations, whichever is the longer, where the

causes of the reduction are clearly reversible AND understood AND ceased, based on (and specifying) any

of the following:

(a) direct observation

(b) an index of abundance appropriate to the taxon

(c) a decline in area of occupancy, extent of occurrence 

and/or quality of habitat

(d) actual or potential levels of exploitation

(e) the effects of introduced taxa, hybridization, pathogens, pollutants, competitors or parasites.

2. An observed, estimated, inferred or suspected population size reduction of ≥80% over the last 10 years or

three generations, whichever is the longer, where the

reduction or its causes may not have ceased OR may

not be understood OR may not be reversible, based on

(and specifying) any of (a) to (e) under A1.

Annex I

IUCN red list categories and criteria (version 3.1)
The Red List of Betulaceae

66

3. A population size reduction of ≥80%, projected or

suspected to be met within the next 10 years or three

generations, whichever is the longer (up to a maximum

of 100 years), based on (and specifying) any of (b) to (e)

under A1.

4. An observed, estimated, inferred, projected or suspected 

population size reduction of ≥80% over any 10 year or

three generation period, whichever is longer (up to a

maximum of 100 years in the future), where the time

period must include both the past and the future, and

where the reduction or its causes may not have ceased

OR may not be understood OR may not be reversible,

based on (and specifying) any of (a) to (e) under A1.

B. Geographic range in the form of either B1 (extent of occurrence) OR B2 (area of occupancy) OR both:

1. Extent of occurrence estimated to be less than 100 km2

,

and estimates indicating at least two of a-c:

a. Severely fragmented or known to exist at only a

single location.

b. Continuing decline, observed, inferred or projected,

in any of the following:

(i) extent of occurrence

(ii) area of occupancy

(iii) area, extent and/or quality of habitat

(iv) number of locations or subpopulations

(v) number of mature individuals.

c. Extreme fluctuations in any of the following:

(i) extent of occurrence

(ii) area of occupancy

(iii) number of locations or subpopulations

(iv)number of mature individuals.

2. Area of occupancy estimated to be less than 10 km2

,

and estimates indicating at least two of a-c:

a. Severely fragmented or known to exist at only a

single location.

b. Continuing decline, observed, inferred or projected,

in any of the following:

(i) extent of occurrence

(ii) area of occupancy

(iii) area, extent and/or quality of habitat

(iv) number of locations or subpopulations

(v) number of mature individuals.

c. Extreme fluctuations in any of the following:

(i) extent of occurrence

(ii) area of occupancy

(iii) number of locations or subpopulations

(iv) number of mature individuals.

C. Population size estimated to number fewer than 250 mature 

individuals and either:

1. An estimated continuing decline of at least 25% within

three years or one generation, whichever is longer, (up

to a maximum of 100 years in the future) OR

2. A continuing decline, observed, projected, or inferred,

in numbers of mature individuals AND at least one of

the following (a-b):

(a) Population structure in the form of one of the following:

(i) no subpopulation estimated to contain more than 

50 mature individuals, OR

(ii) at least 90% of mature individuals in one subpopulation. (b) Extreme fluctuations in number of

mature individuals.

D. Population size estimated to number fewer than 50 mature 

individuals.

E. Quantitative analysis showing the probability of extinction in

the wild is at least 50% within 10 years or three generations, 

whichever is the longer (up to a maximum of 100 years).

ENDANGERED (EN)

A taxon is Endangered when the best available evidence

indicates that it meets any of the following criteria (A to E),

and it is therefore considered to be facing a very high risk of

extinction in the wild:

A. Reduction in population size based on any of the following:

1. An observed, estimated, inferred or suspected population size reduction of ≥70% over the last 10 years

or three generations, whichever is the longer, where

the causes of the reduction are clearly reversible AND

understood AND ceased, based on (and specifying) any

of the following:

(a) direct observation

(b) an index of abundance appropriate to the taxon

(c) a decline in area of occupancy, extent of occurrence 

and/or quality of habitat

(d) actual or potential levels of exploitation

(e) the effects of introduced taxa, hybridization, pathogens, pollutants, competitors or parasites.

2. An observed, estimated, inferred or suspected population size reduction of ≥50% over the last 10 years or

three generations, whichever is the longer, where the

reduction or its causes may not have ceased OR may

not be understood OR may not be reversible, based on

(and specifying) any of (a) to (e) under A1.
The Red List of Betulaceae

67

3. A population size reduction of ≥50%, projected or

suspected to be met within the next 10 years or three

generations, whichever is the longer (up to a maximum

of 100 years), based on (and specifying) any of (b) to (e)

under A1.

4. An observed, estimated, inferred, projected or suspected 

population size reduction of ≥50% over any 10 year or

three generation period, whichever is longer (up to a

maximum of 100 years in the future), where the time

period must include both the past and the future, AND

where the reduction or its causes may not have ceased

OR may not be understood OR may not be reversible,

based on (and specifying) any of (a) to (e) under A1.

B. Geographic range in the form of either B1 (extent of occurrence) OR B2 (area of occupancy) OR both:

1. Extent of occurrence estimated to be less than 5,000

km2

, and estimates indicating at least two of a-c:

a. Severely fragmented or known to exist at no more

than five locations.

b. Continuing decline, observed, inferred or projected,

in any of the following:

(i) extent of occurrence

(ii) area of occupancy

(iii) area, extent and/or quality of habitat

(iv)number of locations or subpopulations

(v) number of mature individuals.

c. Extreme fluctuations in any of the following:

(i) extent of occurrence

(ii) area of occupancy

(iii) number of locations or subpopulations

(iv)number of mature individuals.

2. Area of occupancy estimated to be less than 500 km2

,

and estimates indicating at least two of a-c:

a. Severely fragmented or known to exist at no more

than five locations. b. Continuing decline, observed,

inferred or projected, in any of the following:

(i) extentofoccurrence

(ii) area of occupancy

(iii) area, extent and/or quality of habitat

(iv) number of locations or subpopulations

(v) number of mature individuals.

c. Extreme fluctuations in any of the following:

(i) extent of occurrence

(ii) area of occupancy

(iii) number of locations or subpopulations

(iv)number of mature individuals.

C. Population size estimated to number fewer than 2,500

mature individuals and either:

1. An estimated continuing decline of at least 20% within

five years or two generations, whichever is longer, (up

to a maximum of 100 years in the future) OR

2. A continuing decline, observed, projected, or inferred,

in numbers of mature individuals AND at least one of

the following (a-b):

(a) Population structure in the form of one of the following:

(i) no subpopulation estimated to contain more than 

250 mature individuals, OR

(ii) at least 95% of mature individuals in one subpopulation. (b) Extreme fluctuations in number of

mature individuals.

D. Population size estimated to number fewer than 250 mature 

individuals.

E. Quantitative analysis showing the probability of extinction in

the wild is at least 20% within 20 years or five generations,

whichever is the longer (up to a maximum of 100 years).

VULNERABLE (VU)

A taxon is Vulnerable when the best available evidence indicates that it meets any of the following criteria (A to E), and it

is therefore considered to be facing a high risk of extinction in

the wild:

A. Reduction in population size based on any of the following:

1. An observed, estimated, inferred or suspected population size reduction of ≥50% over the last 10 years

or three generations, whichever is the longer, where

the causes of the reduction are: clearly reversible AND

understood AND ceased, based on (and specifying) any

of the following:

(a) direct observation

(b) an index of abundance appropriate to the taxon

(c) a decline in area of occupancy, extent of occurrence 

and/or quality of habitat

(d) actual or potential levels of exploitation

(e) the effects of introduced taxa, hybridization, pathogens, pollutants, competitors or parasites.

2. An observed, estimated, inferred or suspected population size reduction of ≥30% over the last 10 years or

three generations, whichever is the longer, where the

reduction or its causes may not have ceased OR may

not be understood OR may not be reversible, based on

(and specifying) any of (a) to (e) under A1.
The Red List of Betulaceae

68

3. A population size reduction of ≥30%, projected or

suspected to be met within the next 10 years or three

generations, whichever is the longer (up to a maximum

of 100 years), based on (and specifying) any of (b) to (e)

under A1.

4. An observed, estimated, inferred, projected or suspected 

population size reduction of ≥30% over any 10 year or

three generation period, whichever is longer (up to a

maximum of 100 years in the future), where the time

period must include both the past and the future, AND

where the reduction or its causes may not have ceased

OR may not be understood OR may not be reversible,

based on (and specifying) any of (a) to (e) under A1.

B. Geographic range in the form of either B1 (extent of occurrence) OR B2 (area of occupancy) OR both:

1. Extent of occurrence estimated to be less than 20,000

km2

, and estimates indicating at least two of a-c:

a. Severely fragmented or known to exist at no more

than 10 locations.

b. Continuing decline, observed, inferred or projected,

in any of the following:

(i) extent of occurrence

(ii) area of occupancy

(iii) area, extent and/or quality of habitat

(iv)number of locations or subpopulations

(v) number of mature individuals.

c. Extreme fluctuations in any of the following:

(i) extent of occurrence

(ii) area of occupancy

(iii) number of locations or subpopulations

(iv)number of mature individuals.

2. Area of occupancy estimated to be less than 2,000 km2

,

and estimates indicating at least two of a-c:

a. Severely fragmented or known to exist at no more

than 10 locations.

b. Continuing decline, observed, inferred or projected,

in any of the following:

(i) extent of occurrence

(ii) area of occupancy

(iii) area, extent and/or quality of habitat

(iv)number of locations or subpopulations

(v) number of mature individuals.

c. Extreme fluctuations in any of the following:

(i) extent of occurrence

(ii) area of occupancy

(iii) number of locations or subpopulations

(iv)number of mature individuals.

C. Population size estimated to number fewer than 10,000

mature individuals and either:

1. An estimated continuing decline of at least 10% within

10 years or three generations, whichever is longer, (up

to a maximum of 100 years in the future) OR

2. A continuing decline, observed, projected, or inferred, in 

numbers of mature individuals AND at least one of the 

following (a-b):

(a) Population structure in the form of one of the following:

(i) no subpopulation estimated to contain more than 

1,000 mature individuals, OR

(ii) all mature individuals are in one subpopulation.

(b)Extreme fluctuations in number of mature individuals.

D. Population very small or restricted in the form of either of

the following: 

1. Population size estimated to number fewer than 1,000

mature individuals.

2. Population with a very restricted area of occupancy

(typically less than 20 km2

) or number of locations (typically five or fewer) such that it is prone to the effects of

human activities or stochastic events within a very short

time period in an uncertain future, and is thus capable

of becoming Critically Endangered or even Extinct in a

very short time period.

E. Quantitative analysis showing the probability of extinction

in the wild is at least 10% within 100 years.

Source: IUCN (2001)
The Red List of 

Betulaceae

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