Recovery Plan

for 

 Chorizanthe robusta var. robusta

(Robust Spineflower)

Region 1

U.S. Fish and Wildlife Service

Portland, Oregon

Approved:

Date:
i

DISCLAIMER

Recovery plans delineate reasonable actions that are believed to be required to

recover and/or protect listed species. We, the U.S. Fish and Wildlife Service,

publish recovery plans, sometimes preparing them with the assistance of recovery

teams, contractors, State agencies, and other affected and interested parties. Plans

are reviewed by the public and submitted to additional peer review before we

adopt them. Objectives of the plan will be attained and any necessary funds made

available subject to budgetary and other constraints affecting the parties involved,

as well as the need to address other priorities. Recovery plans do not obligate

other parties to undertake specific actions and may not represent the views nor the

official positions or approval of any individuals or agencies involved in the plan

formulation other than our own. They represent our official position only after

they have been signed by the Regional Director, Director or California/Nevada

Operations Manager as approved. Approved recovery plans are subject to

modification as dictated by new findings, changes in species status, and the

completion of recovery actions.

Literature Citation Should Read As Follows:

U.S. Fish and Wildlife Service. 2004. Recovery Plan for Chorizanthe robusta

var. robusta (Robust Spineflower). U.S. Fish and Wildlife Service,

Portland, Oregon. vii + 71 pages.

An electronic version of this recovery plan will also be made available at:

http://pacific.fws.gov/ecoservices/endangered/recovery/default.htm and at

http://endangered.fws.gov/recovery/index.html#plans.
ii

ACKNOWLEDGMENTS

This recovery plan was prepared by Constance Rutherford, botanist, U.S. Fish and

Wildlife Service, Ventura Fish and Wildlife Office. Kirk Waln of the Ventura

Fish and Wildlife Office produced the maps.

We would like to acknowledge the following people: Dr. Barbara Ertter, Jepson

Herbarium, University of California, Berkeley; and Sandra Baron, Ecologic

Consulting, provided assistance by reviewing an early draft of the recovery plan. 

We appreciate the input and comments we received from Bill Davilla, County of

Santa Cruz, and Kim Tschantz (formerly with the County of Santa Cruz); Susan

Harris and Kirk Lenington, Department of Parks and Recreation, City of Santa

Cruz; Dr. George Gray, Tim Hyland, and Cynthia Roye, California Department of

Parks and Recreation; Laurie Kiguchi, biological consultant; Dean Taylor,

biological consultant; Joe Rigney, Central Coast Wilds; Kathy Lyons, Biotic

Resources Group; Grey Hayes and Randy Morgan, California Native Plant

Society; Michelle Coppoletta and Jane Rodgers, Point Reyes National Seashore;

and Erin Fernandez and Diane Kodama, U.S. Fish and Wildlife Service, San

Francisco Bay National Wildlife Refuge, San Francisco.

We would also like to especially thank Sandra Baron for undertaking research on

insect herbivory of Chorizanthe robusta var. robusta for her Master’s thesis as

well as cheerfully agreeing to adopt several populations to keep an eye on their

status, and to Annie Murphy for undertaking research on the pollination ecology

of C. robusta var. robusta for her Master’s thesis. We are pleased to have made

small financial contributions to these two efforts. We would also like to thank Dr.

Chris Brinegar, San Jose State University, for agreeing to undertake a genetic

study of the taxonomy of C. robusta var. robusta and its close relatives. 
iii

EXECUTIVE SUMMARY

Current Status: Chorizanthe robusta var. robusta (robust spineflower), which is

federally endangered, is restricted to sandy soils along the coast and near-coastal

areas in Santa Cruz and Marin Counties, California. It is currently known from

10 sites that support a total of 12 populations. At the time the draft recovery plan

was prepared, we were only aware of four sites. In the intervening years, greater

awareness of the species generated through the original listing and subsequent

designation of critical habitat has resulted in surveys that have located additional

populations. Of the 10 sites now known, 3 are on park lands (Sunset State Beach,

Santa Cruz County; and Abbots Lagoon and South Kehoe Creek at Point Reyes

National Seashore, Marin County) that support large populations on the order of

10,000 individuals or more. The other seven sites support significantly smaller

populations. Three of these sites are on lands that are or have the potential to be

managed for the conservation of the species: Pogonip Park in the City of Santa

Cruz (including two populations), Ellicott Slough National Wildlife Refuge

(including the Buena Vista and Ellicott populations), and Manresa State Beach. 

The remaining four sites are on private lands with varying opportunities to pursue

conservation activities. These private parcels are named Baldwin Creek,

Branciforte, Aptos, and Freedom. 

Habitat Requirements and Limiting Factors: Chorizanthe robusta var.

robusta is found on sandy soils in coastal and near-coastal areas from Santa Cruz

south to Sunset State Beach in Santa Cruz County, and on Point Reyes National

Seashore in Marin County.

Chorizanthe robusta var. robusta is threatened by urban development,

recreational activities, and competition with nonnative vegetation. In addition,

the low numbers of individuals and populations of this taxon put it at great risk of

extinction due to random, naturally occurring (stochastic) disturbance.

Recovery Priority Number: 9, per criteria published in the Federal Register

(U.S. Fish and Wildlife Service 1983). The priority number indicates that
iv

Chorizanthe robusta var. robusta is an infraspecific taxon with a moderate degree

of threat and a high recovery potential. 

Recovery Goal: The recovery goal for Chorizanthe robusta var. robusta is to

conserve viable and self-sustaining populations in its natural habitat such that

protection of the Endangered Species Act is no longer necessary.

Recovery Criteria:

Chorizanthe robusta var. robusta will be considered for downlisting when:

1) Eleven populations of Chorizanthe robusta var. robusta in four

recovery units distributed through the species’ range have been

protected, either through an approved and implemented

management plan, or through a conservation easement;

2) Habitat in each protected population has been appropriately

managed and restored; and

3) Population monitoring shows a stable or increasing trend in

population size or density over 10 years. 

Chorizanthe robusta var. robusta will be considered for delisting when:

The total number of populations has increased to at least 18, at

least 15 of which have an average population of 1,000 individuals

in a normal rainfall year over at least 10 years beyond the

downlisting monitoring period. This could be achieved by a

combination of the following: a) discovering additional

populations, and/or b) establishing new populations through an

outplanting program. The populations would need to be selfsustaining, and be protected through conservation measures

equivalent to those in the downlisting criteria above. 
v

Actions needed: 

1. Protect existing habitat.

2. Manage existing habitat through implementation plans.

3. Conduct management-oriented research on the taxonomy, ecology,

biology, and management of Chorizanthe robusta var. robusta.

4. Establish new populations within the historical range of the species.

5. Review and revise recovery guidelines.

6. Develop and implement an outreach program.

Date of Downlisting: If the proposed recovery actions are successful and

downlisting criteria are met, downlisting from endangered to threatened could be

considered by 2014; if delisting criteria are met, delisting could be considered by

2024. An evaluation of population viability for Chorizanthe robusta var. robusta

should be done after 5 years to assess the progress that has been made toward

meeting the downlisting criteria, and a more specific target date set at that time. 

Estimated Cost to Achieve Recovery: $376,000 plus costs to be determined.
vi

TABLE OF CONTENTS

I. INTRODUCTION ...............................................1

A. BRIEF OVERVIEW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

B. TAXONOMY AND DESCRIPTION .........................2

C. LIFE HISTORY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

D. HABITAT DESCRIPTION AND CRITICAL HABITAT .........8

E. RANGE AND DISTRIBUTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

F. POPULATION STATUS AND CURRENT THREATS . . . . . . . . . . 17

G. CONSERVATION MEASURES . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

1. Available Laws, Regulations, and Ordinances . . . . . . . . . . . . 27

2. Conservation Measures Undertaken . . . . . . . . . . . . . . . . . . . . 32

3. Potential Mitigation Measures . . . . . . . . . . . . . . . . . . . . . . . . 33

H. RECOVERY STRATEGY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

II. RECOVERY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

A. RECOVERY GOAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

B. RECOVERY OBJECTIVES AND CRITERIA . . . . . . . . . . . . . . . . . 40

III. STEPDOWN NARRATIVE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

IV. IMPLEMENTATION SCHEDULE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

V. REFERENCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

A. LITERATURE CITED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

B. IN LITT. REFERENCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

C. PERSONAL COMMUNICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . 64

VI. APPENDICES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65

APPENDIX A. Explanation of Recovery Priority System . . . . . . . . . . . 65

APPENDIX B: Historical collections of Chorizanthe robusta var. robusta

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66

APPENDIX C: Summary of Agency, Peer, and Public comments on the

Draft Recovery Plan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68

APPENDIX D: Threats identified for Chorizanthe robusta var. robusta

and Recovery Plan Recommended Management Actions . . . . . . 70
vii

LIST OF TABLES 

Table 1. Key to varieties of Chorizanthe robusta, Chorizanthe pungens, and

related species . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Table 2. The status of 12 extant populations of Chorizanthe robusta var.

robusta . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Table 3. Acreage of critical habitat designated for Chorizanthe robusta var.

robusta, by landowner. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Table 4. Geographic recovery units for recovery planning. . . . . . . . . . . . 36

Table 5. Recovery goals for each geographic unit . . . . . . . . . . . . . . . . . . . 41

LIST OF FIGURES

Figure 1. Illustration of Chorizanthe robusta var. robusta ..............3

Figure 2. Distribution of Chorizanthe robusta var. robusta . . . . . . . . . . . . 13

Figure 3. Location of Chorizanthe robusta var. robusta populations in Santa

Cruz County, California . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Figure 4. Location of Chorizanthe robusta var. robusta populations in Marin

County, California . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
1

I. INTRODUCTION

A. BRIEF OVERVIEW

Chorizanthe robusta var. robusta (robust spineflower) is restricted to sandy soils

along the coast and near-coastal areas in Santa Cruz and Marin Counties,

California. We published the final rule determining its Federal endangered status

in the Federal Register on February 4, 1994 (U.S. Fish and Wildlife Service

1994); this rule listed the entire species C. robusta as endangered, including both

C. robusta var. robusta and C. robusta var. hartwegii (Scotts Valley spineflower). 

Recovery criteria and actions pertaining to C. robusta var. hartwegii have

previously been fully addressed in the Recovery Plan for Insect and Plant Taxa

from the Santa Cruz Mountains in California (U.S. Fish and Wildlife Service

1999). Because C. robusta var. robusta is geographically and ecologically

distinct from C. robusta var. hartwegii, its recovery needs are being addressed

separately in this recovery plan. 

The draft recovery plan for Chorizanthe robusta var. robusta (U.S. Fish and

Wildlife Service 2000a) was released for agency and public comment in

September of 2000 (U.S. Fish and Wildlife Service 2000b). As a result of a

lawsuit settlement, we published a proposed critical habitat designation in

February 2001, and the final critical habitat designation in May 2002 (U.S. Fish

and Wildlife Service 2002). During the course of designating critical habitat, we

obtained new information concerning the status and distribution of C. robusta var.

robusta. Therefore, this final recovery plan includes a number of changes from

the draft recovery plan. These can be summarized as follows:
2

! seven new populations are described

! additional information concerning the life history is included

! a section on critical habitat and special management considerations has

been added

Chorizanthe robusta var. robusta has a recovery priority of 9. Recovery priorities

for listed species range from 1 to 18, with 1 being the highest priority. A priority

of 9 indicates a subspecies facing a moderate degree of threat and a high potential

for recovery (see Appendix A). We have lowered the recovery priority to 9 from

the previously published priority number of 3 in the draft recovery plan because

the discovery of seven additional populations, two of which are quite large, has

reduced the degree of threat from high to moderate. 

B. TAXONOMY AND DESCRIPTION

The robust spineflower was first described as Chorizanthe robusta by Charles

Parry in 1889 based on a collection he made 6 years earlier “north of Aptos along

Monterey Bay” (Parry 1889). Willis Jepson considered it to be a variety of

C. pungens and thus combined the taxon under the name C. pungens var. robusta

in his Flora of California in 1913 (Jepson 1913). In their revision of the genus in

1989, Reveal and Hardham (1989) recognized Parry’s treatment and retained the

taxon as C. robusta. Shortly thereafter, Reveal and Morgan (1989) described a

variety of C. robusta, the variety hartwegii, from the Santa Cruz Mountains

(Scotts Valley spineflower). The coastal variety of this species is recognized as

Chorizanthe robusta var. robusta (Figure 1).

Chorizanthe robusta var. robusta is an annual spineflower in the Pungentes

section of the genus Chorizanthe in the buckwheat family (Polygonaceae) (Figure

1). Like other spineflowers, it is branched from the base and subtended by a

rosette of basal leaves. The plant has an erect to spreading or prostrate habit,

usually standing not more than 20 centimeters (8 inches) high. The whorl of 
3

Figure 1. Illustration of Chorizanthe robusta var. robusta. Illustration by

Sharon Erspamer. Used with permission of the City of Santa Cruz.
4

bracts subtending the flowers (involucres) has thin white to pinkish scarious (thin

and translucent) margins along the basal portions of the teeth. Relative to other

spineflower taxa in the Pungentes section, the flower heads are large (1.5 to 2.0

centimeters [0.6 to 0.8 inch]) in diameter and distinctly aggregate.

 Because of the close relationship between several species of Chorizanthe in the

Pungentes section and the plasticity of some of the morphological characteristics

used to identify them, there has been confusion as to the identity of certain

specimens that have been collected (Ertter 1990, 1996). In particular, specimens

collected from the coastal dune areas near Sunset State Beach and just inland near

Rob Roy Junction and Buena Vista have been variously identified as C. pungens

var. pungens (Monterey spineflower) (Bill Davilla, Ecosystems West, pers.

comm. 1998) or C. robusta var. robusta (S. Baron in litt. 1995, Morgan and

Kiguchi 1995, California Natural Diversity Data Base 1997). Moreover, Ertter

has pointed out that there is another coastal “phase” of Chorizanthe, which may

be distinct from both Monterey spineflower and robust spineflower, and which

keys out as Monterey spineflower with the current identification key (Hickman

1993).

Since the draft recovery plan was prepared, two additional populations of

spineflower located at Point Reyes National Seashore have been identified as

Chorizanthe robusta var. robusta by Ertter (B. Ertter in litt. 2001). These new

populations co-occur with C. cuspidata var. cuspidata (San Francisco Bay

spineflower) and C. cuspidata var. villosa (woolly-headed spineflower), two other

members of the Pungentes complex (J. Rodgers in litt. 2003). 

To assist in distinguishing between the varieties of Chorizanthe in the Pungentes

section that have hooked involucral teeth, Barbara Ertter (in litt. 1997) has

prepared a key to distinguish between these taxa (Table 1). Experts, however,

acknowledge that the distinction between species in the Pungentes section of the

genus in the Monterey Bay area merits additional attention (Ertter 1990, 1996). 

In addition, the recent discovery of C. robusta var. robusta co-occurring with

other members of the Pungentes section at Point Reyes National Seashore may

pose a similar challenge.
5

Table 1. Key to varieties of Chorizanthe robusta, C. pungens, and related species of

subsect. Pungentes with hooked involucral teeth. Based in part on Reveal and

Hardham 1989, Reveal and Morgan 1989; as modified by B. Ertter in litt. 1997.

1. Plants erect, up to 5 dm high; heads distinct,1-2 cm wide; involucres with a white to pink or purplish scarious

margin

2. Heads > 1 cm wide, white or rose; involucres 2.5-4 mm long; tepals erose to denticulate or distinctly

cuspidate . . . C. robusta C. Parry

3. Heads ca. 1.5-2 cm wide, white; hills from Santa Cruz to Aptos, historically in Alameda and

Colma . . . C. robusta var. robusta [phase 1]

3' Heads ca. 1-1.5 cm wide, rose-pink; Santa Cruz Mts. near Scotts Valley.. . . C. robusta var.

hartwegii (Benth.) Rev. & R. Morgan [phase 2]

2' Heads to 1 cm wide, pink; involucres 2-2.5(3) mm long; tepals erose apically, not cuspidate; Santa

Cruz Mountains . . . C. pungens Benth. var. hartwegiana Rev. & Hardham [phase3]

1' Plants prostrate or decumbent to ascending, mostly less than 2.5 dm high; heads often indistinct, if distinct then

to 1 cm wide 

4. Involucres 3-4 mm long, bordered with a conspicuous white margin; heads indistinct; lower end of

Salinas Valley from Watsonville to Montery Peninsula . . . C. robusta var. nov.? [phase 5]

4' Involucres 1.5-2.5(3) mm long, with or without a scarious margin; heads indistinct or distinct

5. Tepals erose to cuspidate apically, the flowers white to rose, pubescent, 2-3 (3.5) mm long;

involucral tube with or without a scarious margin; stamens 3 or 6-9

6. Tepals erose apically, not cuspidate; involucral teeth uncinate; Santa Cruz and

Monterey cos. south to Santa Barbara Co.

7. Involucres distinctly margined, the margin white or pink, the tube 2-2.5(3)

mm long, the anterior awn 2-3 mm long; flowers 2-3.5 mm long; stamens 9;

coastal beaches and inland mountains of Monterey and Santa Cruz cos. . . .

C. pungens Benth.

8. Involucral lobes with white (rarely pinkish) scarious margins;

plants prostrate to slightly ascending; heads distinct or indistinct;

coastal areas and inland into Salinas Valley . . . C. pungens var.

pungens [phase 4]

8' Involucral lobes with pinkish scarious margins; plants slightly

ascending to erect; heads distinct; Santa Cruz Mountains . . .

C. pungens Benth. var. hartwegiana Rev. & Hardham [phase3]

7' Involucres not margined (or if so, then the margin pinkish but hardly

conspicuous), the tube1.5-2(2.5) mm long, the anterior awn 1.5-2.5 mm long;

flowers 2-3 mm long; stamens 3 or 6-9; coastal mesas and foothills of San

Luis Obispo and Santa Barbara cos. . . . C. angustifolia Nutt.

6' Tepals cuspidate, pubescent the entire length with the hairs usually extending

beyond the apex; involucres 1.5-3 mm long, the awns uncinate or straight, with or

without scarious margins, the anterior awn 2-3 mm long; flowers 2-3 mm long; San

Francisco peninsula from northern San Mateo Co., northward to Marin and Sonoma

cos., historically in Alameda . . . C. cuspidata S. Watson

5' Tepals entire apically, the flowers distinctly bicolored with a lemon-yellow tube and white

lobes, glabrous, 2.5-3 mm long; involucral tube with a distinct scarious margin; stamens 3-9;

foothills and mountains of the Coast Ranges from Santa Cruz and Monterey cos. southward

through San Luis Obispo to western Santa Barbara Co. . . . C. diffusa Benth.
6

The resolution of taxonomic issues will bear upon the recovery of Chorizanthe

robusta var. robusta and closely related taxa in several ways. If, in the future,

taxonomic studies indicate that C. robusta var. robusta is even more narrowly

defined than it is at present, certain recovery actions (e.g., introductions to

historical or other suitable sites) will need to ensure that the correct taxa are being

utilized. In addition, the status of any taxa at sites that had been previously

identified as supporting C. robusta var. robusta will have to be reevaluated. 

Should these taxa be as rare as or rarer than C. robusta var. robusta, then the

conservation and recovery measures for them would be similar to those outlined

in this recovery plan. If taxonomic studies indicate that C. robusta var. robusta is

more broadly defined than previously believed, this knowledge may change our

view of how aggressive we need to be with recovery actions. We believe that

clarifying the taxonomic relationships between members of the Pungentes section

and assessing the true status of C. robusta var. robusta and other related sensitive

taxa is a pivotal task that should be undertaken as soon as possible. 

C. LIFE HISTORY

Chorizanthe robusta var. robusta is a short-lived annual plant. It germinates

during the winter months and generally flowers from April through June;

however, if climatic conditions are favorable, some individuals may continue to

flower throughout the summer. Murphy (2003) expanded on observations of

pollinators initiated by S. Baron (in litt. 2000) and R. Morgan (pers comm. 2000). 

At the two sites she observed (Sunset Beach and Pogonip), insects from the orders

Diptera, Hymenoptera, Lepidoptera, and Coleoptera were frequent visitors. In

addition Hemiptera (true bugs) were also frequent visitors to C. robusta var

robusta at Pogonip (Murphy 2003). Within these orders, 14 insect families were

frequent visitors at Sunset, and 13 frequent families at Pogonip. The diversity of

insects found on this plant is comparable to that of some other generalist

pollination systems. 

Murphy (2003) researched several aspects of Chorizanthe robusta var. robusta

pollination ecology. She found that inflorescences where pollinators were

excluded, and that therefore were only self-pollinated, had only 19 percent of the

seed set found in inflorescences where pollinators were not excluded. Therefore,
7

although C. robusta var. robusta is self-compatible, insect pollination greatly

increases seed production. The germination rates of the seed resulting from selfpollination was not significantly different from seed resulting from crosspollination by insects, though it is possible that if there were a reduced fitness of 

seed resulting from self-pollination, it may show up in later stages of plant

development. In an often cool and windy environment, such as along the coast,

pollinators may be unreliable. The ability to self-pollinate ensures that some

amount of seed set will occur if cross pollination by insects does not occur

(Moldenke 1976). Murphy observed that the probability of any one flower being

visited by a pollinator was lower at the coastal site (Sunset) than at the more

inland site (Pogonip).

In other annual species of Chorizanthe, the flowers are protandrous, a

reproductive strategy in which the anthers (part of flower that produces pollen)

mature and shed pollen prior to the maturation of the style (part of the female

reproductive structure of a flower) to receive pollen, with a delay of style

receptivity of 1 or 2 days. Protandry facilitates cross-pollination by insects. 

However, if cross-pollination does not occur within 1 or 2 days, self-pollination

may occur as the flower closes at the end of the day (Reveal 2001). Murphy also

found that, while C. robusta var. robusta is protandrous like other species in the

genus, self-pollination cannot occur until the third and last day of flowering,

which may indicate an even greater propensity for outcrossing. 

Baron (1998) tracked the phenology of 100 individual Chorizanthe robusta var.

robusta seedlings on the Buena Vista parcel in 1997. Out of 100 seedlings, 42

percent survived to flowering. Causes of mortality included desiccation prior to

flowering (52 percent), herbivory (4 percent), and uprooting by gophers

(Thomomys bottae) (2 percent). Among plants that survived to flowering, flower

production was positively correlated with basal diameter, with the largest

individuals producing upwards of 50 flowers; each flower produces one seed.

Seed is mature by August. The plants turn a rusty hue as they dry through the

summer months, eventually shattering during the fall. Seed dispersal is facilitated

by the involucral spines, which attach the seed to passing animals. Rabbits

(Sylvilagus bachmani) have been observed to browse on Chorizanthe robusta var.
8

robusta (Baron 2002), and most likely act to disperse seeds as well. Other small

mammals (such as fox, coyotes, ground squirrels, skunks, racoons, and

chipmunks) and birds are potential seed dispersers. While animal vectors most

likely facilitate dispersal between populations, or within portions of populations,

the prevailing coastal winds undoubtedly play a part in scattering seed within

colonies and populations.

Maintaining a seed bank (a reserve of dormant seeds, generally found in the soil)

is important to the year-to-year and long-term survival of annual plants (Baskin

and Baskin 1975, Baskin and Baskin 1998). A seed bank includes all the mature

seeds in a population and generally covers a larger area than the extent of

observable plants seen in a given year (Given 1994). The number and location of

standing plants (the observable plants) in a population varies annually due to a

number of factors, including the amount and timing of rainfall, temperature, soil

conditions, and the extent and nature of the seed bank. The extent of seed bank

reserves are variable from population to population and large fluctuations in the

number of standing plants at a given site may occur from one year to the next.

Herbivory by insects could reduce population viability of Chorizanthe robusta

var. robusta by reducing seed output. Baron (2002) also compared seed output of

patches of C. robusta var. robusta where microlepidopteran larvae in the genus

Aroga (Gelichiidae) were excluded and compared the seed output to patches

where the larvae were allowed to forage, and found a 58 percent increase in seed

output in the former. In addition, rabbits removed seed heads from 11 percent of

the plants under study. 

D. HABITAT DESCRIPTION AND CRITICAL HABITAT

The designation of critical habitat for Chorizanthe robusta var. robusta provided

the opportunity to look more closely at the physical and biological characteristics

of habitat (called the primary constituent elements) that are essential to the

conservation of the species, and that may require special management. We

identified four primary constituent elements in the critical habitat designation for

C. robusta var. robusta:
9

1. Sandy soils associated with active coastal dunes and inland sites with

sandy soils. The origin of the soils, whether from active dunes or interior fossil

dunes, appears unimportant. The most prevalent soil series represented are

Baywood, Ben Lomond, Zayante, Tierra, and Watsonville. At Pogonip, the sandy

soils are thought to be derived from the Santa Margarita sandstone formation

(John Gilchrist and Associates 1986, Habitat Restoration Group 1996). Sandy

soils tend to be nutrient-poor, which limits the abundance of other herbaceous

species that can grow on them. Onsite accumulation of duff and litter or the

addition of nutrients (e.g., fertilizers) to these naturally nutrient-poor soils may

allow for the establishment of other competing species. 

2. Plant communities that support associated species, including coastal dune,

coastal scrub, grassland, maritime chaparral, and oak woodland

communities, and have a structure such that there are openings between the

dominant elements (e.g., scrub, shrub, oak trees, clumps of herbaceous

vegetation). The species found associated with Chorizanthe robusta var. robusta

vary according to the plant communities present at each site. For instance, at

Sunset State Beach, coastal scrub species include Eriophyllum staechadifolium

(seaside woolly sunflower), Artemisia pycnocephala (coastal sagewort),

Ericameria ericoides (mock heather), and Baccharis pilularis (coyote bush). In

open patches between these shrubs, Chorizanthe robusta var. robusta occurs with

other herbs and grasses including the following: Camissonia chieranthifolia

(beach evening primrose), Eschscholzia californica (California poppy), Linaria

canadensis (blue toadflax), Cryptantha sp. (cryptantha), Lupinus sp. (lupine),

Gnaphalium bicolor (Bioletti’s cudweed), and the nonnative grasses Avena fatua

(wild oats) and Bromus diandrus (ripgut brome). The closely-related and

federally threatened Chorizanthe pungens var. pungens (Monterey spineflower)

grows in a band parallel to Chorizanthe robusta var. robusta in the foredunes

along the beach, and the federally endangered Gilia tenuiflora var. arenaria (sand

gilia) occurs sympatrically with Chorizanthe robusta var. robusta in one location

(California Natural Diversity Data Base 1997, S. Baron in litt. 1999b).

On more inland sites (Pogonip, Buena Vista, and Freedom), Chorizanthe robusta

var. robusta inhabits sandy soils in openings surrounded by coastal scrub,

chaparral, or woodland plant communities. Associated species at the Pogonip site
10

include Briza mazima (rattlesnake grass), Avena fatua, Aira caryophyllea

(European hair grass), Filago gallica (narrow-leaved filago), Lotus strigosus

(Bishop’s lotus), and Rumex acetosella (sheep sorrel) (S. Baron in litt. 1999a). 

The federally-listed Ohlone tiger beetle (Cicindela ohlone) also occurs at the

Pogonip site. At the Freedom site, Chorizanthe robusta var. robusta grows in a

grass-dominated opening in oak woodland and scrub (California Natural

Diversity Data Base 1997).

At the Buena Vista site, Chorizanthe robusta var. robusta grows on sandy soils in

openings within oak forest and maritime chaparral. The northernmost extent of

this uncommon chaparral type occurs at the Buena Vista site and the surrounding

area, and includes Arctostaphylos hookeri (Hooker’s manzanita) and Ceanothus

cuneatus var. rigidus (Monterey ceanothus), both species of concern (Van Dyke

and Holl 2003), and Baccharis pilularis and Pteridium aquilinum (bracken fern). 

Species found associated with Chorizanthe robusta var. robusta include

Hypochaeris glabra (smooth cat’s-ear), Clarkia purpurea ssp. quadrivulnera

(four-spot), Erodium cicutarium (filaree), Horkelia sp. (horkelia), Gnaphalium

purpureum (purple cudweed), Lotus strigosus, L. scoparius (deerweed), and

native and nonnative grasses. Plants were also observed in disturbed areas,

“along trails, and where gopher disturbance is high” (S. Baron in litt. 1998). The

Buena Vista site also supports the federally endangered Santa Cruz long-toed

salamander (Ambystoma macrodactylum). The Buena Vista parcel begins 0.4

kilometer (0.25 mile) northeast of the Santa Cruz Long-toed Salamander State

Ecological Reserve’s Ellicott Pond Unit and was recently acquired by the Ellicott

Slough National Wildlife Refuge. 

3. Plant communities that contain little or no cover by nonnative species

which would compete for resources available for growth and reproduction of

Chorizanthe robusta var. robusta. In areas where the sandy soils have been

enriched, either through the accumulation of organic matter or importation of

other soils, these sandy soils may support abundant herbaceous vegetation which

may then compete with Chorizanthe robusta var. robusta.

4. Physical processes, such as occasional soil disturbance that support

natural dune dynamics along coastal areas. Because Chorizanthe robusta var.
11

robusta, like other members of the Chorizanthe genus, does not compete well

with other species, maintaining areas free of cover and shade from other plants is

essential for its long-term persistence. On the coast at Sunset State Beach,

C. robusta var. robusta tends to grow at the base of backdunes in openings of

coastal scrub. Dune dynamics include the deposition of sands along the shoreline,

which are then blown onshore by the prevailing winds. Dunes can be mobile,

with actively migrating younger dunes overriding and partially burying older

ones, or older dunes may develop blowouts, which reactivate dune mobility. A

reduction in the sand source or physical controls, such as the stabilization of

dunes through planting of vegetation, can slow the natural dynamic dune

processes (U.S. Fish and Wildlife Service 1998a).

Special Management Considerations or Protections

In addition to identifying the primary constituent elements for Chorizanthe

robusta var. robusta, we have attempted to identify special management

considerations or protections that designated critical habitat areas may need in

order to ensure that the primary constituent elements are being maintained. In the

critical habitat designation for this species, we discussed the six most likely kinds

of special management and protection that C. robusta var. robusta may require:

(1) In near-coastal areas, the supply and movement of sand along the

coast must be maintained to create the dynamic dune habitats that are needed for

Chorizanthe robusta var. robusta.

(2) In more interior locations, the sandy soils on which Chorizanthe

robusta var. robusta is found should be maintained to optimize conditions for the

species. Physical properties of the soil, such as its chemical composition, salinity,

and drainage capabilities would best be maintained by limiting or restricting the

use of herbicides, fertilizers, or other soil amendments.

(3) The associated plant communities must be maintained to ensure that

the habitat needs of pollinators and dispersal agents are maintained. The use of

pesticides should be limited or restricted so that viable populations of pollinators

are present to facilitate reproduction of Chorizanthe robusta var. robusta. 
12

Fragmentation of habitat through construction of roads and certain types of

fencing should be limited so that seed dispersal agents may move seed of

C. robusta var. robusta throughout the unit.

(4) In some plant communities, it may be important to maintain a mosaic

of different-aged stands of coastal scrub or maritime chaparral patches so that

openings that support Chorizanthe robusta var. robusta will be maintained. 

Depending on location, the use of prescribed fire, thinning, or other forms of

vegetation management may be useful in creating and maintaining this type of

mosaic.

(5) In all plant communities where Chorizanthe robusta var. robusta

occurs, invasive, nonnative species such as Phalaris aquaticus (harding grass),

Ehrharta spp. (veldt grass), Ammophila arenaria (European beachgrass),

Carpobrotus spp. (iceplant), and other species need to be actively managed to

maintain the open habitat that C. robusta var. robusta needs.

(6) Certain areas where Chorizanthe robusta var. robusta occurs may

need to be fenced to protect them from accidental or intentional trampling by

humans and livestock. While C. robusta var. robusta appears to withstand light

to moderate disturbance, heavy disturbance may be detrimental to its persistence. 

Seasonal exclusions may work in certain areas to protect C. robusta var. robusta

during its critical season of growth and reproduction.

E. RANGE AND DISTRIBUTION

According to information collated by the California Natural Diversity Data Base

(1997), Chorizanthe robusta var. robusta once ranged from Alameda County, on

the eastern side of San Francisco Bay, south to Monterey County - a range of 100

kilometers (65 miles) (Figure 2). However, the identity of the Alameda

collections is still unresolved; Reveal and Hardham (1989) noted that these

collections may be more closely related to C. cuspidata or C. valida, but that

resolution of the question is unlikely since the Alameda population was last

collected in 1948 and no longer exists. Aside from the Alameda collections, it is

interesting to note that some of the other historical collections were located at 
Monterey

Santa Cruz

King City

Salinas

San Lucas

Soledad

Los Gatos

San

Francisco

Oakland

Point Reyes

San Jose

MONTEREY

COUNTY

SONOMA

COUNTY

NAPA

COUNTY

SAN BENITO

COUNTY

SOLANO

COUNTY

SANTA CLARA

COUNTY

MARIN

COUNTY

ALAMEDA

COUNTY

CONTRA COSTA

COUNTY

SAN MATEO

COUNTY

SANTA CRUZ

COUNTY

0 25 50

Miles

AREA

OF

DETAIL

0 12.5 25 50

Kilometers

U.S. Fish & Wildlife Service, July, 2004

Figure 2. Distribution of Robust Spineflower

Current Robust Spineflower Locations

Recorded Since 1979

Robust Spineflower Locations

Recorded Prior to 1979

13
14

sites farther inland (e.g. Felton, Los Gatos) than those from where C. robusta var.

robusta is currently known. A partial list of historical and current population

locations that have been documented by herbarium collections and noted in the

California Natural Diversity Data Base are included in Appendix B. 

In 2001, collections of a spineflower gathered near Abbott’s Lagoon in Point

Reyes National Seashore, Marin County, were identified as Chorizanthe robusta

var. robusta (B. Ertter in litt. 2001). The discovery of two populations here is

puzzling, not only because they occur outside the known historical range of the

taxon and are 100 miles away from the populations in Santa Cruz County, but

because they are in an area that has been the subject of previous plant surveys. 

They may have been overlooked because they looked similar to other Chorizanthe

taxa that occur in the area (J. Rodgers in litt. 2003). These two populations

collectively totaled 10,000 individuals in 2002; the large numbers of individuals

contained in these new populations is significant relative to the total number of

individuals. 

In addition to the two populations at Point Reyes National Seashore, we became

aware of information concerning five other populations during the process of

designating critical habitat for Chorizanthe robusta var. robusta that we were not

aware of during preparation of the draft recovery plan. Three of these populations

(Baldwin Creek, Branciforte, and Aptos) are new locations not previously

described. While only scant information about the fourth population at Manresa

was available at that time, the additional information available since then has

been sufficient to confirm the existence of the population. The fifth new

population was found at Ellicot Slough National Wildlife Refuge within the past

few years; it is adjacent to populations on the Buena Vista parcel. 

In summary, Chorizanthe robusta var. robusta is known from sandy soils along

and adjacent to the coast of southern Santa Cruz County (ten populations) and

Marin County (two populations). The distance between the southern- and

northernmost populations in Santa Cruz County is approximately 30 kilometers

(20 miles), while the distance between this cluster and the Point Reyes

populations is approximately 160 kilometers (100 miles). The distribution of

these populations is portrayed in Figures 3 and 4.
Santa Cruz Aptos

Capitola

Watsonville

Manresa

Baldwin Creek

The Forest

of Nisene Marks

State Park

Wilder Ranch

State Park

Henry Cowell

Redwoods

State Park

Ellicot Slough

NWR

Monterey Co.

Freedom

Blvd.

Tro u t Gulch Rd.

Pogonip

Sunset

Aptos

Buena Vista

Freedom

Branciforte

U.S. Fish & Wildlife Service June, 2003

Area

of

Detail

Monterey Bay

0 0.5 1 2 3 4 5 6 7 8 9

Kilometers

0 1.5 3 4.5 6

Miles

Note: Critical habitat has been designated for 6 of these sites, and therefore we have

llustrated critical habitat boudaries for these populations. The remaining 2 populations

(Baldwin Creek and Manresa) are portrayed with dots.

Parks and Refuges

Developed Areas

Populations Defined by Boundaries

of Robust Spineflower Critical Habitat Units

Populations Not in Robust Spineflower

Critical Habitat

Figure 3. Location of Chorizanthe robusta var. 

robusta populations in Santa Cruz County, California 

15
South

Kehoe

Creek

Abbott's

Lagoon

Sir Francis Drake Blvd. Pi erce Point Rd.

Tomales

Point Reyes

Station

Area

of

Detail

Drakes Bay

U.S. Fish & Wildlife Service June, 2003

0 0.5 1 2 3 4 5 6

Kilometers

0 1.25 2.5 3.75 5

Miles

Tomales Bay

P

a

c

i

f

i

c

O

c

e

a

n

Tomales Bay

State Park

State Park Lands

Point Reyes National Seashore

Point Reyes Wilderness (NPS)

Robust Spineflower Populations

Figure 4. Location of Chorizanthe robusta

var. robusta Populations in Marin County, 

California 

16
17

F. POPULATION STATUS AND CURRENT THREATS

Many of the sites where Chorizanthe robusta var. robusta historically occurred

have been modified by development and agriculture. Because many of the

historical collections include only general locality information, i.e. “Colma” or

“Los Gatos”, it is impossible to determine when or how these populations were

extirpated. However, a typical pattern of land use may have included initial

conversion of wild lands to orchards, field crops, or grazing lands, followed by

urban development.

The final rule listing this taxon in 1994 discussed the threats facing the four

populations of Chorizanthe robusta var. robusta that were known at the time (the

two Pogonip populations were considered jointly); these threats were continuing

loss of habitat from residential and golf course development, recreational use, and

competition with nonnative species. In addition, this taxon is vulnerable to

extirpation by random (stochastic) events. The current status of the 12

populations is summarized in Table 2; threats are discussed below:

 Listing Factor (A): The Present or Threatened Destruction, Modification, or

Curtailment of Its Habitat or Range

As suggested by the numerous historical locations from which Chorizanthe

robusta var. robusta was once collected, many populations were extirpated by

urbanization or from conversion of native habitat to agriculture. However, even

where native habitat remains, natural succession leading to an increase in cover

by native herbaceous and shrubby vegetation may shade out C. robusta var.

robusta. Prior to European colonization of California, C. robusta var. robusta,

like other members of the genus, most likely relied on natural disturbances such

as natural dune erosion and formation along the coast, and in more inland areas,

fires that created openings in native grassland, shrubland, and oak woodland

habitats. 

At some locations, invasive, nonnative species may rapidly move into

Chorizanthe robusta var. robusta habitat, resulting in the reduction or elimination

of Chorizanthe robusta var. robusta from that site. Nonnative species that have 
18

Table 2. The status of 12 currently known populations for Chorizanthe robusta var. robusta. Only 

significant threats (Listing Factors A and E) are addressed here. See text for more discuss

Population Population ID

number andLocation1

CriticalHabitatDesignation

Area ofStandingPlants2

Number ofIndividuals

CurrentThreats

Severity of CurrentThreats3

ConsEffor

A E

1 6. Pogonip Park 1,

south of BrayshawTrail, City of SantaCruz, Santa CruzCounty

61.5 hectares(152 acres)

0.7 sq.meter (7.5sq. feet)

40 (1990)136 (2000)230 (2002)271 (2004)

/ / Recreation / L

random events / H

DesigMana

2 7. Pogonip Park 2,

west of Nature LoopTrail, City of SantaCruz, Santa CruzCounty

(included inabove)

6 sq. meters(60 sq. feet)

300 (1990)675 (2000)553 (2002)595 (2004)

/ / Recreation / L

random events / H

DesigMana

3 10. Sunset Beach

State Park, SantaCruz County

34.8 hectares(86 acres)

1 kilometer(0.62 mile)

5,000 (1988)100,000 (1995)1 mil. (1998)

/ recreation / L

restoration activities / L

Dune populadapt

3 14. South end of

Sunset State Beach,Santa Cruz County 

(included inabove)

(see above) 300 (1985)

0 (1990)

/ recreation / L

restoration activities / L

Dune populadapt

4 15. Buena Vista

parcel, Santa CruzCounty

54.6 hectares(135 acres)

4 hectares(10 acres)

1,000 (1993)1,500 (1999)3,700 (2003)

/ / development (golf

course) / Lrandom events / H

AcquRefug

5 Ellicott Slough

National WildlifeRefuge

none 2 hectares

(5 acres)

?? (2003) / vegetation

management/Lrecreation/L

manaRefug

6 16. Freedom4,

northeast of RobRoy Junction, SantaCruz County

4 hectares(10 acres)

1.2 hectares(3 acres)

6,000+(1993)2,200 (2001)

/ / human disturbance / H none
Population Population ID

number andLocation1

CriticalHabitatDesignation

Area ofStandingPlants2

Number ofIndividuals

CurrentThreats

Severity of CurrentThreats3

ConsEffor

A E

19

7 Aptos, Santa Cruz

County

28.3 hectares(70 acres)

?? 3,000 (2000) / / recreation/L

vegetation mgmt/Lrandom events / L

---

8 Branciforte, City of

Santa Cruz, SantaCruz County

3.6 hectares(9 acres)

0.4 hectare(1 acre)

1,000 (2002) / / development / H

recreation / H

City orestor

9 Baldwin Creek,

Santa Cruz County

none 0.4 hectare

(1 acre)

1,000 (2001) / / road maintenance / L

random events /M 

---

10 Manresa State

Beach, Santa CruzCounty

none 1122 sq

meters(1340 sqyards)

2,000 to 20,000(2002)

/ / recreation / L

random events / M

Eucalmonit

11 Abbott’s Lagoon -Pt

Reyes NationalSeashore, MarinCounty

none 19.4 hectare

(48 acres)

> 10,000 (2002) / recreation / L

agriculture/Mgrazing/M

Basel2003

12 South Kehoe Creek

- Pt Reyes NationalSeashore, MarinCounty

none 9 hectares

(22 acres)

thousands (2002) / recreation / L

grazing/Mroadside mowing/L

Basel2003

1 Population ID number = number assigned to the population in the California Natural Diversity Data Base.2 If area covered by a population was not included in occurrence reports, our staff estimated area from maps.3 Threat Severity codes: H = high; M = moderate; L = low4 Previously called “Aptos” in the draft recovery plan.

*TPL = Trust for Public Lands; USFWS = U.S. Fish and Wildlife Service
20

invaded habitat of Chorizanthe robusta var. robusta include Eucalyptus globulus

(eucalyptus), Carpobrotus edulis and Carpobrotus chilensis (iceplant),

Ammophila arenaria, Genista monspessulana (French broom), Heterotheca

grandiflora (telegraph weed), and nonnative Bromus ssp. (brome grasses) (L.

Kiguchi in litt. 2000, K. Lyons in litt. 2001, Hyland 2003). 

Because many of the areas where Chorizanthe robusta var. robusta occurs have

been invaded by nonnative species, long-term management activities may be

necessary to maintain the open conditions in which C. robusta var. robusta can

persist. One of the populations at Point Reyes National Seashore occurs within an 

old agricultural field that is tilled annually. Although the native habitat has been

altered by agricultural practices, C. robusta var. robusta has most likely survived

because the annual tilling provided the disturbance that reduced the cover of

plants that would otherwise compete with it. Likewise, removal of the shrub

overstory along the Pacific Gas & Electric powerline right-of-way for fuels

management at the Aptos site has most likely favored the persistence of

C. robusta var. robusta.

Recreational activities such as hiking at the various park units (Pogonip, Sunset

and Manresa State Beaches, and Point Reyes National Seashore) likely have a

slight impact on Chorizanthe robusta var. robusta habitat through trampling. 

Though no research has been done, field biologists familiar with the species think

that low to moderate levels of impacts may benefit C. robusta var. robusta by

reducing cover from other species, while high levels of impact may eliminate

C. robusta var. robusta as well. Other more intensive forms of recreation, such as

horseback riding and mountain bike riding, may not be compatible with the longterm conservation of C. robusta var. robusta.

Two of the sites on private land have been subjected to additional, potentially

serious threats. The Branciforte parcel in the City of Santa Cruz has been

targeted for high density development. We have met with the City of Santa Cruz

and representatives of the landowner to discuss several options, including setting

aside the entire parcel as a low-impact neighborhood park with a portion set aside

for the conservation of Chorizanthe robusta var. robusta habitat, or in the event

that development goes forward, to overlay a similar conservation set-aside area. 
21

In the winter of 2003, neighborhood children dug pits and built up mounds on a

site where C. robusta var. robusta occurred to construct a bicycle course. The

extent of damage, and whether the site can be restored, is unknown at this time.

Individuals of Chorizanthe robusta var. robusta at the Freedom site sustained

damage in the late 1990's when Aptos High School widened a narrow foot path

into a path wide enough for a vehicle. The population still persists on both sides

of the path on high school property, as well as on an adjacent private parcel. 

 

Listing Factor (B): Overutilization for Commercial, Recreational, Scientific, or

Educational Purposes

Overutilization for any commercial, recreational, scientific, or educational

purpose was not considered a threat at the time of listing, and is not considered a

threat at the current time. 

Listing Factor (C): Disease or Predation

Disease or predation were not considered a threat at the time or listing, nor at the

current time. However, recent research on herbivory of Chorizanthe robusta var.

robusta at Sunset State Beach found that individual plants with an insect

herbivore (a microlepidopteran larva in the genus Aroga [Geliechiidae]) had a

lower seed output than those plants that were treated with a pesticide (Baron

2002). Larval-infested plants tended to be found in larger plant patches (mean =

6 square meters [54 square feet]) than noninfested plants. We do not know

whether this same insect herbivore occurs within other populations of C. robusta

var. robusta.

Baron (2002) also observed that 11 percent of the plants in her study had seed

heads removed by rabbits. For grazing, rabbits appear to favor smaller, rather

than larger, plant patches that had a mean size of about 0.8 square meter (9 square

feet); ungrazed patches had a mean size of 4 square meters (50 square feet). 

Although rabbits graze on seed heads, they are also likely responsible for carrying

seed on their fur, and therefore dispersing seed between patches. 
22

Both populations of Chorizanthe robusta var. robusta at Point Reyes National

Seashore are located partially within pastures that are grazed by cattle from spring

through the fall season. Presumably, the timing and intensity of grazing is such

that C. robusta var. robusta has been able to persist at these locations. The extent

to which cattle graze on C. robusta var. robusta is unknown at this time.

Listing Factor (D): The Inadequacy of Existing Regulatory Mechanisms

At the time of listing, Chorizanthe robusta var. robusta received minimal

protection from existing Federal, State, and local laws, regulations, and

ordinances. The Federal listing in 1994 and the designation of critical habitat in

2002 provided additional opportunities to achieve conservation for the species by

raising the awareness of local regulatory agencies to the importance of

maintaining its habitat, and by accessing Federal and State programs that allow

private landowners and local agencies to implement conservation and restoration

activities. These actions are discussed further in the Conservation Measures

section below. 

Listing Factor (E): Other Natural or Manmade Factors Affecting its Continued

Existence

Shade Intolerance

Research on a related species of spineflower, Chorizanthe pungens var.

hartwegiana (Ben Lomond spineflower), indicated that seedling survivorship,

growth, and reproduction was more limited by shading conditions than by soil

type (McGraw and Levin 1998). These findings are in alignment with

observations that, when found growing in coastal scrub or chaparral habitats,

C. robusta var. robusta occurs in the openings between shrubs. 

Competition with nonnative annual species

Competition with nonnative species may be a threat. We do not know for certain

to what extent Chorizanthe robusta var. robusta competes, in the traditional

sense, for sunlight, water, soil, and nutrient resources with other plant taxa. In

addition to the shade intolerance exhibited by seedlings, we also surmise that

seeds of C. robusta var. robusta are not likely to germinate if the soil surface is
23

shaded, whether the shade is provided by “competing” annual species or by an

adjacent shrub canopy.

Random extinction

Species with few populations and individuals are vulnerable to the threat of

naturally occurring events causing extinction through mechanisms operating

either at the genetic level, the population level, or the landscape level. Decrease

in genetic variability will reduce the likelihood that individuals in a population

will persist in a changing environment, and are more likely to experience reduced

reproductive success due to inbreeding depression. We have recently initiated an

investigation into the genetic characteristics of Chorizanthe robusta var. robusta;

however, at this point in time the degree to which these characteristics contribute

to the likelihood of C. robusta var. robusta being vulnerable to extinction for

these reasons is unknown. 

Species with few populations or those that are low in number may be subject to

forces at the population level that affect their ability to complete their life cycles

successfully. For example, reduced numbers of individuals may lead to a

reduction in number of pollinators and subsequently seed set. Additionally, if the

host plants are partially self-incompatible, reduction in population size may lead

to increased self-pollination and may reduce the level of genetic variability. At

the landscape level, random natural events, such as storms, drought, or fire, could

destroy a significant percentage of individuals or entire populations; a hot fire

could destroy a seedbank as well. Five populations of Chorizanthe robusta var.

robusta support on the order of 1,000 individuals or less. The restriction of

colonies to small sites increases their risk of extinction from such naturally

occurring events.

 

The current status of, and threats facing, the 12 existing populations are

summarized in Table 2. The two colonies at Pogonip Park appear to be stable, but

are vulnerable to extirpation due to the small numbers of individuals and the

small area of habitat that they occupy. The City of Santa Cruz Recreation

Department (1998) has developed a Master Plan for the Park, which includes

measures to protect the two colonies (see Conservation Measures section). A
24

total of 64 hectares (159 acres) of critical habitat were designated for Chorizanthe

robusta var. robusta at this site (U.S. Fish and Wildlife Service 2002). 

The population at Sunset State Beach is the largest, both in numbers of

individuals (100,000+) and extent (1.0 kilometer [0.6 mile]), and is therefore

more secure than the other populations. Some recreational activities and invasion

of nonnative species, including Ammophila arenaria, Ehrharta calycina (veldt

grass), and Carpobrotus edulis (iceplant), have affected portions of its habitat at

this site. However, the California Department of Parks and Recreation has been

aggressive in their efforts to remove nonnative species, and have established a

monitoring program to track the status of the population (California Department

of Parks and Recreation 2003). Thirty-five hectares (86 acres) of critical habitat

were designated for Chorizanthe robusta var. robusta at this site (U.S. Fish and

Wildlife Service 2002).

The population at Buena Vista consisted of 1,000 individuals in 1993, 1,000

individuals in 1997, 305 in 2000, and 3,700 in 2003 (California Natural Diversity

Data Base 1997; Baron in litt. 1998, 2003). This parcel was slated for golf course

development in the 1990's. After many years of effort, this parcel was purchased

in 2004 for the conservation of several sensitive species, including Chorizanthe

robusta var. robusta and the Santa Cruz long-toed salamander. The Trust for

Public Land, California Department of Fish and Game, the California Wildlife

Conservation Board, the California Coastal Conservancy, and the Service

contributed funds toward the acquisition of this parcel (U.S. Fish and Wildlife

Service 1998b, 2003). Fifty-five hectares (135 acres) of critical habitat were

designated for C. robusta var. robusta at this site (U.S. Fish and Wildlife Service

2002). Another small population of C. robusta var. robusta was observed at

Ellicott Slough National Wildlife Refuge in 2002, less than 1 mile from the

populations on the Buena Vista parcel.

The Freedom population near Rob Roy Junction has fluctuated from 2,200 to

upwards of 10,000 individuals over the past decade (Morgan and Kiguchi 1995,

K. Lyons in litt. 2001). The Freedom population is bisected by a trail. A portion

of a privately owned 8-hectare (20-acre) site was scraped in the early 1990's in

preparation for a lot split, and an unknown number of plants were destroyed. 
25

However, Chorizanthe robusta var. robusta has apparently recolonized the

scraped area (1997). A portion of the population is located on adjacent Aptos

High School lands owned by the Pajaro Unified School District. At some time

during the late 1990's, the school widened what was once a narrow path through

the spineflower population into a path wide enough for a vehicle (L. Kiguchi in

litt. 2000); the path and the adjacent hillsides receive some recreational use from

high school students. Four hectares (10 acres) of critical habitat were designated

for C. robusta var. robusta at this site (U.S. Fish and Wildlife Service 2002). 

Subsequent surveys have determined that additional colonies of C. robusta var.

robusta occur in the adjacent area and outside the critical habitat boundary (V.

Cheap in litt. 2001).

The Aptos population occurs on privately owned land, along a utilities corridor

right-of-way managed by Pacific Gas & Electric Company. The population was

located in 2000 in preparation for a pole replacement project (D. Taylor in litt.

2000). At that time, the population was estimated to comprise 3,000 individuals. 

Other activities along the corridor included vegetation management to reduce fuel

loads, and casual recreational use by local residents (R. Witthaus, Pacific Gas &

Electric, pers. comm. 2003). Twenty-eight hectares (70 acres) of critical habitat

were designated for Chorizanthe robusta var. robusta at this site (U.S. Fish and

Wildlife Service 2002).

The Branciforte population occurs on private land along Carbonero Creek within

the City of Santa Cruz. This population was located in 2000 during a stream

survey, and numbers between 1,000 and 2,000 individuals (R. Morgan, pers.

comm. 2000). Despite our efforts to encourage the City of Santa Cruz to acquire

the 4-hectare (9-acre) parcel for a low impact park, plans are being developed to

construct high density housing. During the spring of 2003, local residents

established a dirt bike course on top of the Chorizanthe robusta var. robusta

population. Four hectares (9 acres) of critical habitat was designated for

C. robusta var. robusta at this site (U.S. Fish and Wildlife Service 2002).

The Baldwin Creek population was located in the late 1990's near the headwaters

of Baldwin Creek on a private parcel adjacent to Wilder Ranch State Park, about

5 miles north-northwest of the City of Santa Cruz. The area receives some use
26

from the landowner and local residents (tree thinning and road maintenance), and

roads and trails bisect several colonies. Because this site is fairly remote from

population centers, no major changes in land use are anticipated at this time. The

population was estimated to be between 1,000 and 1,500 individuals in 2001 (E.

Grumbine in litt. 2003). Critical habitat was not designated at this site because no

documentation for the population was available at the time the critical habitat

designation was prepared (U.S. Fish and Wildlife Service 2002).

The Manresa State Beach population is the most seaward of all Chorizanthe

robusta var. robusta populations, as it occurs in loose sand at the base of

sloughing cliff faces and on cutbanks of a nearby trail that cuts from the top of the

cliff down to the beach. The California Department of Parks and Recreation has,

and is continuing to remove Carpobrotus spp. from C. robusta var. robusta

habitat. In addition, a Eucalyptus grove that surrounds the beach trail is being

thinned and contained to limit its spread into C. robusta var. robusta habitat. 

Fencing intended to deter beachgoers from descending the cliffs provide partial

protection to the populations along the cliff front. In 2003, California Department

of Parks and Recreation mapped the areal extent of standing plants as covering

1,122 square meters (12,070 square feet). The population is estimated to

comprise a minimum of 2,000 individuals, and possibly as many as 20,000

(Hyland 2003). Critical habitat was not designated at this site because of

confusion over the identity of the spineflower at Manresa State Beach at the time

the critical habitat designation was prepared (U.S. Fish and Wildlife Service

2002).

Two population sites occur at Point Reyes National Seashore. The Abbott’s

Lagoon population covers approximately 19 hectares (48 acres). The largest

portion of this population was fenced off from grazing in the early 1990's, and is

going through succession toward coastal sage scrub. A smaller portion of the

population occurs within a field that is planted with annual grasses, grazed, and

plowed on an annual cycle. In addition, a portion of the population that occurs

along a roadside is mowed on an annual basis. The south Kehoe Creek

population is in a field that is grazed by cattle from spring through the fall season,

and roadside mowing also occurs in a portion of the population (M. Coppoletta in

litt. 2003, J. Rodgers in litt. 2003). Chorizanthe robusta var. robusta was not
27

identified from these sites earlier because they co-occur with another spineflower,

C. cuspidata. These populations may well be even more extensive than is

currently known, and additional surveys are planned for 2003. Point Reyes

National Seashore is also developing a management plan for the two populations. 

Critical habitat was not designated at this site because documentation for the

populations was not available at the time the critical habitat designation was

prepared (U.S. Fish and Wildlife Service 2002).

G. CONSERVATION MEASURES

1. Available Laws, Regulations, and Ordinances

Federal Level 

U.S. Fish and Wildlife Service

Chorizanthe robusta var. robusta was listed as an endangered species on February

4, 1994 (U.S. Fish and Wildlife Service 1994). Section 4 of the Endangered

Species Act of 1973, as amended, requires us to develop a recovery plan that

describes “site-specific management actions” necessary for the conservation and

survival of listed species. The plan must have “objective, measurable criteria

which, when met” will allow C. robusta var. robusta to be removed from the

Federal list. The plan must estimate the time needed, and the cost to carry out the

conservation measures. After C. robusta var. robusta is removed from the list,

we must, in cooperation with the State of California, “effectively monitor for not

less than 5 years” the status of Chorizanthe robusta var. robusta, and we must be

prepared to restore the taxon to the list if necessary. 

In 1999 we were legally challenged on our decision not to designate critical

habitat at the time of listing. Therefore, we proposed critical habitat on February

15, 2001, and published a final critical habitat designation on May 28, 2002 (U.S.

Fish and Wildlife Service 2002). Critical habitat is defined as the specific areas

within the geographic area occupied by a species on which are found the physical

or biological features (primary constituent elements) essential to the conservation

of the species and that may require special management considerations or
28

protection, and specific areas outside the geographic area occupied by a species

upon a determination that such areas are essential for the conservation of the

species.

In the critical habitat designation, we identified the following four primary

constituent elements:

1. Sandy soils associated with active coastal dunes and inland sites with sandy

soils;

2. Plant communities that support associated species, including coastal dune,

coastal scrub, grassland, maritime chaparral, and oak woodland communities, and

have a structure such that there are openings between the dominant elements;

3. Plant communities that contain little or no cover by nonnative species which

would compete for resources available for growth and reproduction with

Chorizanthe robusta var. robusta; and

4. Physical processes, such as occasional soil disturbance, that support natural

dune dynamics along coastal areas. 

At the time the proposed critical habitat designation was prepared we only had

adequate documentation for six critical habitat units. The designation of critical

habitat is not intended to indicate that such lands are the only lands that are

important to the recovery of the species, or that recovery activities can only take

place on these lands. For instance, certain recovery actions, such as attempting

establishment of new populations within historical range, may need to be done on

lands that have not been specifically identified at this point in time. Other

recovery actions, such as restoration, could occur on other sites that support

Chorizanthe robusta var. robusta that were not included in the critical habitat

designation, or on other sites where C. robusta var. robusta may be discovered in

the future. The acreage designated as critical habitat is summarized in Table 3

below. 
29

Table 3. Acreage of Critical Habitat designated for Chorizanthe robusta var.

robusta, by Landowner

Unit Name State Private City/Local Total

A. Pogonip 2 ha (7 ac) 62 ha (152 ac) 64 ha (159 ac) 

B. Branciforte 4 ha (9 ac) 4 ha (9 ac) 

C. Aptos 28 ha (70 ac) 28 ha(70 ac)

D. Freedom 4 ha (9 ac) 0.4 ha (1 ac) 4 ha(10 ac) 

E. Buena Vista 55 ha (135 ac) 55 ha (135 ac) 

F. Sunset 35 ha (86 ac) 35 ha (86 ac)

TOTAL 35 ha (86 ac) 93 ha (230 ac) 62 ha (153 ac) 190 ha (469 ac)

Other provisions of the Endangered Species Act may also apply; some of these

may assist us in the conservation and recovery of Chorizanthe robusta var.

robusta:

/ Section 5 of the Endangered Species Act authorizes the Department of the

Interior to acquire habitat essential to preserving listed endangered

species. 

/ Section 6 of the Endangered Species Act directs us to cooperate with the

States to maintain adequate programs for the conservation of listed

species. 

/ Section 7(a) of the Endangered Species Act requires Federal agencies to

use their authorities to carry out programs for the conservation of listed

species and to consult with us whenever they may affect listed species or

their critical habitat. 

/ Section 9 of the Endangered Species Act describes prohibited acts with

respect to threatened and endangered species. In general, plant species

receive fewer protections than wildlife species primarily because the

Endangered Species Act does not address the issue of “take” for plant

species. On Federal lands or lands under Federal jurisdiction, it is a
30

violation to remove and reduce threatened or endangered plants to

possession, or to maliciously damage or destroy them. On other lands,

endangered plants may not be removed, cut, dug up, or damaged in

knowing violation of any State law or regulation. Endangered plants also

cannot be sold, shipped, or received in interstate or foreign commerce. 

/ Section 10 of the Endangered Species Act details the exceptions to section

9 permitted in the form of recovery and incidental take permits. For plant

taxa, the primary benefit of section 10 is derived from the issuance of

permits for two purposes: 1) to carry out research or recovery activities

that may involve removal of plants from Federal land, and 2) by our

policy, the inclusion of conservation measures for plants within a habitat

conservation plan which is required for the “incidental take” of wildlife

species in the course of an otherwise lawful activity through a section 10

(a)(1)(B) permit.

Point Reyes National Seashore

In addition to complying with Federal laws such as the Endangered Species Act

and the National Environmental Policy Act, the National Park Service also has

general guidelines for natural resources management (National Park Service

1991), and the National Park Service Statement for Management (National Park

Service 1985). Point Reyes National Seashore also has developed a management

plan that addresses management needs of sensitive plant species (National Park

Service 1980). 

State Level

At the State level, the California Environmental Quality Act provides some

protection for endangered species through the environmental review process. 

Initially, a public agency reviews a project to determine if it would negatively

impact any State- or federally-listed species. If the negative project impacts are

not considered significant, a formal environmental impact report is not required,

and the project is granted a Negative Declaration with measures/recommendations

to reduce environmental impacts. If the project’s impacts are considered
31

significant, an environmental impact report is required, consisting of a description

of existing site conditions, impact analysis, and detailed mitigation measures that

would reduce project impacts to a less-than-significant level. Mitigation

measures such as avoidance, fencing, or landowner education programs must be

incorporated into the approved project, and may provide long-term species

protection. But if no mitigation measures are feasible and if the lead agency

determines that benefits of the project outweigh the environmental risks, it may

approve a project that has significant environmental effects by making a statement

of overriding considerations.

California Department of Parks and Recreation policy states that one of their

goals is “... in concert with other agencies and organizations, to acquire and

preserve outstanding examples of California species; and to acquire and

perpetuate significant natural plant communities, associations, and examples of

rare, endangered, or otherwise sensitive native California plants, as indicated on

State and Federal lists” (Policy II.4, amended 5-4-94) (State Park and Recreation

Commission 1994). A brief management plan has been developed for the Sunset

State Beach Park Unit (California Department of Parks and Recreation 1998), but

the California Department of Parks and Recreation acknowledges that this plan

should be expanded (G. Gray in litt. 2000). 

Private Land 

For private property under the purview of the County of Santa Cruz (Freedom,

Valencia, and Baldwin Creek), the General Code 16.32 of the County of Santa

Cruz (Santa Cruz County 1994) applies. It allows only resource-dependent uses

within environmentally sensitive habitat areas, including habitat for rare and

endangered species. For proposed land divisions or developments, the County

requires protection of environmentally sensitive habitats through dedication of an

open space or conservation easement to protect the portion of a sensitive habitat

that is undisturbed by the proposed development.

The Coastal Zone Management Act of 1972 is a Federal statute that allowed for

the establishment of the California Coastal Act of 1976. The California Coastal

Act established a coastal zone within which development is planned and
32

regulated. As required by the California Coastal Act, Santa Cruz County has

developed a Coastal Land Use Plan, and it is incorporated into their County Land

Use Plan (Santa Cruz County 1994). Changes to the general plan designations or

zoning must be approved by the County and then certified by the California

Coastal Commission. Land use decisions made by the County in the Coastal

Zone are appealable to the California Coastal Commission. Although the Coastal

Zone designation and California Environmental Quality Act require that unique

biological resources such as Chorizanthe robusta var. robusta are considered in

the planning process, any protection offered by these regulatory mechanisms is

ultimately at the discretion of the local and State agencies involved.

The Environmental Quality Element of the General Plan for the City of Santa

Cruz contains the following policy with respect to listed species: “Continue the

protection of rare, endangered, sensitive, and limited species and habitats

supporting them. . ..”. The Santa Cruz Municipal Code (section 24.14.080) also

states that construction, grading, or removal of vegetation is not permitted within

wildlife habitats and plant communities where there are federally listed or other

sensitive species prior to receiving jurisdictional permits for their removal (S.

Brown in litt. 2003). These policies apply to the Pogonip and Branciforte sites,

and any other site within the City’s purview that may be found in the future. 

2. Conservation Measures Undertaken

Federal

Our Refuges Division identified the Buena Vista site as a priority for addition to

the Ellicott Slough National Wildlife Refuge (U.S. Fish and Wildlife Service

1998b); the Trust for Public Lands and other agencies and organizations assisted

us in acquisition of this site. Expansion of the Refuge will benefit current efforts

to protect habitat which would maintain and enhance populations of the Santa

Cruz long-toed salamander, the California tiger salamander (Ambystoma

californiense), and Chorizanthe robusta var. robusta.

Point Reyes National Seashore has initiated development of a management plan

and monitoring protocol for the two populations on their lands. Additional
33

surveys will also be conducted in conjunction with the California Native Plant

Society to locate other populations on suitable habitat.

State

At Sunset State Beach and Manresa State Beach, the California Department of

Parks and Recreation has been actively restoring dune habitat for approximately

12 years, primarily focusing on the removal of nonnative Carpobrotus spp. and

Ammophila arenaria. In addition, isolated patches of Ehrharta calcina and

Eucalyptus that are invading Chorizanthe robusta var. robusta habitat are also

being controlled. California Department of Parks and Recreation has also

initiated a long-term monitoring program for Chorizanthe robusta var. robusta at

Sunset State Beach, and is planning on establishing a monitoring program at

Manresa State Beach as well.

Local.

The City of Santa Cruz has developed a Master Plan that calls for managing the

Pogonip property primarily as a "low impact" park (City of Santa Cruz Recreation

Department 1998). The Master Plan specifies four management actions for

Chorizanthe robusta var. robusta habitat: 1) develop a management program

with the California Department of Fish and Game to ensure long-term survival of

the two habitat areas for C. robusta var. robusta, 2) gather and record census data

on populations, 3) monitor pedestrian trail use along the Pogonip Creek Nature

Trail to determine extent of impacts, and 4) install educational signs near habitat

on the Pogonip Creek Nature Trail. The City has carried out annual monitoring,

but other management actions have not been taken up to this point because the

populations appear to be stable and are not sustaining any recreational impacts. 

Due to budget shortages the City has reduced its Parks staff, which currently

restricts the implementation of oversight and management.

3. Potential Mitigation Measures 

If projects are proposed that will adversely affect Chorizanthe robusta var.

robusta or its habitat, every effort should be made to avoid direct impacts. If
34

direct avoidance of the C. robusta var. robusta population is not possible,

mitigation efforts should try to reduce negative impacts to an insignificant level

and possibly enhance C. robusta var. robusta habitat. Conditions should be

incorporated into the plan prior to approval. Because there are so few populations

of C. robusta var. robusta, and it is a short-lived annual species, every attempt

should be made to maintain existing populations and associated habitat with

minimal disturbance. Certain restoration efforts, such as removal of nonnative

species, may be appropriate. However, transplanting of seed or individuals has

generally been unsuccessful in establishing self-sustaining populations (Fiedler

1991), and should not be used as mitigation unless success has been proven

before the project is implemented and any disturbance to the population occurs. 

Possible Mitigation Measures for Chorizanthe robusta var. robusta

a. If Chorizanthe robusta var. robusta is thought to occur on the site,

confirmation from a qualified botanist should be obtained first.

b. If the proposed project will directly remove part or all of a

Chorizanthe robusta var. robusta population, reconfigure project to avoid

such direct impacts.

c. If the proposed project will have secondary impacts in the form of

alteration of ecologic processes (hydrology, edaphic conditions, pollinator

availability) on part or all of a site supporting a population, reconfigure

the project to avoid such secondary impacts.

d. If the proposed project will have secondary impacts in the form of

increasing traffic from humans, bicycles, horses, and pets, use fencing,

barriers, and signing as appropriate to reduce such impacts.

e. If the proposed project will impact habitat through application of

herbicides or pesticides, either through runoff or overspray, reconfigure

the project to avoid such impacts.
35

f. If the proposed project will have secondary impacts in the form of

increasing opportunities for the encroachment of nonnative plants,

measures should be taken to minimize the effects, including limiting new

landscaping to native species, using only appropriate local native species

in seed mixes, and including weed control measures in restoration efforts.

g. If the proposed project will have temporary impacts on part or all of a

site supporting a population of Chorizanthe robusta var. robusta, make

efforts to minimize temporary impacts, and take steps to restore the site if

this can be done without causing further long-term damage.

H. RECOVERY STRATEGY

Summary of Status. Based on available information, Chorizanthe robusta var.

robusta once ranged over five counties, from the San Francisco Bay area south to

Monterey County (see Figure 2). The recent discovery of C. robusta var. robusta

at Point Reyes National Seashore has increased this range north to Marin County,

on the north side of the San Francisco Bay. However, intervening populations

from San Mateo, Santa Clara, and Alameda Counties have disappeared. 

The large size of Chorizanthe robusta var. robusta populations recently found at

Point Reyes National Seashore also significantly alters our view of the status of

the taxon overall. The overall numbers of individuals are larger than previously

known. However, the geographic distribution is such that the largest populations

are found at the very northern and very southern end of the plant’s distribution. 

Other populations are not only small, but they are concentrated in the Santa Cruz

area. 

With the discovery of new populations on National Park Service lands, the

opportunity to conserve and manage Chorizanthe robusta var. robusta

populations on park and refuge lands has increased. Although impacts associated

with recreation and restoration activities do occur on the these parcels, the

greatest human-related threats to C. robusta var. robusta remain on the three

parcels of private land where the plant’s habitat is impacted by development and

associated secondary impacts. Low numbers of individuals in all but the largest
36

populations at Point Reyes National Seashore and Sunset State Beach remain a

concern due to the potential for local extirpations. 

Recovery Strategy. Maintaining the geographic distribution of Chorizanthe

robusta var. robusta needs to be a key factor in the recovery strategy for this

plant. The presence of large populations at Point Reyes National Seashore and

Sunset State Beach provide some level of confidence that C. robusta var. robusta

will not go extinct in the near future. However, much genetic variability, and

with it, the opportunity to contribute to the long-term survival of the plant could

be lost if the smaller populations clustered around Santa Cruz are allowed to go

extinct. Therefore, criteria for recovery should focus on maintaining populations

within all the portions of the range of the plant. We have grouped the 12

populations into 4 geographic recovery units as described in Table 4 below.

Table 4. Geographic recovery units for recovery planning. 

Recovery Unit Populations

Point Reyes South Kehoe Creek, Abbotts Lagoon

Northern Santa Cruz Baldwin Creek, Pogonip 1, Pogonip 2, Branciforte

Aptos Freedom, Aptos

Southern Santa Cruz Buena Vista, Ellicott, Manresa State Beach, Sunset

State Beach

Specific efforts should focus on conserving, managing, and enhancing currently

known habitat throughout the range of the species, conducting managementoriented research, and reestablishing populations within the historical range of the

species if appropriate habitat can be located. We advocate an adaptive

management approach, wherein management is modified if monitoring indicates

that objectives to attain the desired condition have not been met, or if newly

available information indicates that objectives need to be modified. The priorities

for achieving recovery are as follows:
37

1. Protect habitat for Chorizanthe robusta var. robusta at all existing sites. 

Protection of Chorizanthe robusta var. robusta habitat at the various park and

refuge sites should be achievable because each of the managing agencies have

within their mandates the protection of sensitive resources. These sites include

Pogonip Park (City of Santa Cruz), Sunset State Beach and Manresa State Beach

(California Department of Parks and Recreation), Abbott’s Lagoon and South

Kehoe Creek (Point Reyes National Seashore), and Buena Vista and Ellicott

Slough (Ellicott Slough National Wildlife Refuge).

Achieving protection for populations on private lands is more problematic. City

of Santa Cruz and County of Santa Cruz authorities for conservation of sensitive

resources include the use of conservation easements and other tools to ensure that

future development does not impact habitat for Chorizanthe robusta var. robusta

on private lands. In addition to regulating future activities, all interested parties,

including us, California Department of Fish and Game, the County, and

nongovernmental organizations such as the Trust for Public Lands, California

Native Plant Society, and The Land Trust of Santa Cruz County should work

together to acquire key parcels for conservation and recovery of C. robusta var.

robusta.

2. Manage habitat for Chorizanthe robusta var. robusta at existing sites. Habitat

that is under protective status should be managed to ensure that ecosystem

processes vital to the long-term survival of Chorizanthe robusta var. robusta are

allowed to function. Such ecosystem processes include edaphic and hydrologic

function, nutrient cycling, pollinator activity, and seed dispersal mechanisms. 

Management plans should be developed and implemented for specific sites that

identify the most appropriate activities for maintaining ecosystem function and

habitat enhancement. 

Activities to maintain ecologic functions and to achieve habitat enhancement

could include: controlled burning, reduction of nonnative plant invasion, and

control of recreational activities that would cause undue soil erosion or

compaction. For additional discussion on potential management needs, see the

earlier section on Special Management Considerations.
38

3. Conduct management-oriented research. Research on Chorizanthe robusta

var. robusta that contributes to a better understanding of what it requires for longterm viability is needed for developing and revising more appropriate

management goals, and to assist in evaluating potential habitat for introduction. 

Taxonomic studies are needed to identify the phenotype/genotype of the 12

known populations, and populations at other historical or new sites that are

located in the future. Life history studies of Chorizanthe robusta var. robusta are

needed to determine which of its characteristics affect its persistence. Habitat

characterization studies are needed, particularly focusing on edaphic and

hydrologic conditions, plant community associations, and seed characteristics.

Additional research on pollination ecology should be carried out to build on the

studies done by Murphy (2003). Research needs include understanding how

C. robusta var. robusta responds to different types and intensities of natural and

managed disturbance.

4. Establish populations in appropriate habitat within the historical range of the

species. Attempting to establish new populations can be expensive, logistically

difficult, and is rarely successful (Fiedler 1991, Falk and Olwell 1992). This

effort should be considered because, although large populations exist at the

northern and southern extremes of its range (Point Reyes National Seashore and

Sunset State Beach, respectively), the nine other populations clustered in the

Santa Cruz area comprise small numbers of individuals and small amounts of

habitat and are vulnerable to extirpation from random events. Many of the sites

where Chorizanthe robusta var. robusta was historically collected no longer

provide suitable habitat. However, an assessment of other possible suitable sites

should be conducted to determine if an outplanting program is feasible.

5. Review and revise recovery criteria as new information becomes available.

Based on the effectiveness of the efforts to preserve and manage habitat, to

establish new populations within the historical range of the taxon, and the

information resulting from research, recovery criteria and recovery actions for

Chorizanthe robusta var. robusta should be revised in the future, as necessary.
39

6. Develop and implement an outreach program. Increasing public awareness of

this variety of spineflower will facilitate efforts to preserve it and associated

habitat. Brochures can be prepared and distributed at Pogonip Park, Sunset State

Beach, Manresa State Beach, Point Reyes National Seashore, Ellicott Slough

National Wildlife Refuge, and to private landowners with potential habitat to

enlist the public in efforts to conserve Chorizanthe robusta var. robusta. 

Educational signs can also be posted at appropriate locations on park lands.
40

II. RECOVERY

A. RECOVERY GOAL

The recovery goal for Chorizanthe robusta var. robusta is to conserve viable selfsustaining populations in its natural habitat such that protection of the Endangered

Species Act is no longer necessary.

B. RECOVERY OBJECTIVES AND CRITERIA

Objectives: The objectives for the recovery of this species are first to reclassify

its status from endangered to threatened, and ultimately to delist it completely. 

Reclassification criteria can be quantified in terms of: 1) minimum numbers of

individuals and populations, 2) abundance and distribution of habitat, 3) its ability

to be self-sustaining and survive over some period of time, and 4) the removal or

management of potential threats. 

Preliminary Downlisting Criteria:

1. Within each recovery unit, the number of populations and acreage of

occupied habitat for each population has been protected as specified in

Table 5 below.

2. Habitat in each protected population has been appropriately managed

and restored.

3. Population monitoring shows a stable or increasing trend in population

size or density during favorable precipitation years over at least 10 years.

3a. For populations under 4 hectares (10 acres) and below 10,000

individuals, the average number of individuals in favorable (nondrought) precipitation years should meet or exceed the target

population levels given in Table 5 during a period of at least 10

years that encompass a normal rainfall cycle (including periods of

drought and wet years). Zedler and Black (1989) analyzed

historical precipitation records for San Diego and calculated the 
41

Table 5. Recovery goals for each geographic recovery unit.

Recovery Unit Population Conservation Achieved

Through: 

A) approved and

implemented

management plan with

monitoring, or

B) conservation

easement

Maintain

Occupied

Habitat

Maintain

Target # of

Individuals

A. Point Reyes Abbott’s Lagoon A 48 acres 10,000

South Kehoe

Creek

A 22 acres current

number

(“thousands”)

combined total maintain 2 of 2 70 acres 10,000+

B. Northern

Santa Cruz

Baldwin Creek B ?? 1000

Pogonip 1 A habitat limited

to 0.25 acre

100

Pogonip 2 A habitat limited

to 1 acre

500

Branciforte B habitat limited

to 1 acre

1000

combined total maintain 3 of 4 2 acres

C. Aptos Aptos A 10 acres 2000

Freedom B 5 acres 2000

combined total maintain 2 of 2 15 acres

D. Southern

Santa Cruz

Buena Vista A 12 acres 1500

Ellicott Slough A 2 acres 500

Manresa State

Beach

A 5 acres 2,000 - 20,000

Sunset State

Beach

A 50 acres 10,000

combined total maintain 4 of 4 60 acres 10,000
42

minimum monitoring period that would be needed to expect a range of

annual rainfall that includes 50 percent of the total range in variation

of annual rainfall. An analogous period should be calculated for the

central coastal California area where Chorizanthe robusta var. robusta

occurs, and the 10-year monitoring period should be reassessed if it

would not adequately capture the range of precipitation in the region.

3b. For populations over 10,000 individuals or 4 hectares (10 acres),

monitoring based on density or frequency may be more appropriate. 

Currently, this would apply to populations at Sunset State Beach,

Abbott’s Lagoon, South Kehoe Creek, and possibly Aptos and Buena

Vista.

Delisting Criteria:

In addition to the above, achieve the following:

1. The total number of populations has increased to at least 18, at least 15 of

which have an average population of 1,000 individuals in favorable (nondrought) rainfall years over at least 10 years (beyond the downlisting

monitoring period). 

We selected the target of 18 populations based on the goal of maintaining the

taxon within each of the four geographic recovery units depending on the

number, size, and level of protection that is afforded current populations in

each of those units, as follows: Point Reyes unit - increase populations by 0;

Northern Santa Cruz unit - increase populations by 3; Aptos unit - increase

populations by 3; Southern Santa Cruz unit - increase populations by 0. Note

that if the target number of 18 populations is reached, the newly discovered or

newly established populations will not necessarily be distributed within these

units as we are defining them now.

This criterion could be achieved by a combination of the following: 

a. discovering additional populations and achieving an equivalent

level of conservation for them as above.

b. establishing new populations through an outplanting program. The

populations would need to be self-sustaining, and be protected through
43

conservation measures equivalent to above. Surveys should be

conducted within the species’ historical range to determine the

availability and defensibility of suitable habitat. Priority should be

placed on establishing populations within the historical range of the

species as well as in the two geographic recovery units (Northern

Santa Cruz and Aptos) that have smaller populations, if suitable

habitat can be located.

All of these criteria should be reevaluated and updated as new information about the

species and its habitat becomes available.
44

III. STEPDOWN NARRATIVE

1. Protect habitat with existing Chorizanthe robusta var. robusta

populations.

Chorizanthe robusta var. robusta populations and habitat on park and refuge lands

are afforded some level of protection, which we expect will continue. Those

populations on private lands are the most vulnerable to human impacts. Populations

on private lands include Baldwin Creek, Branciforte, Freedom, and Aptos. 

1.1 Inform landowners

Affected private landowners should be informed of efforts to recover

Chorizanthe robusta var. robusta, invited to participate in recovery efforts,

and be asked to prevent inadvertent or intentional destruction of habitat. 

Affected private landowners include:

Baldwin Creek: Campbell

Branciforte: First Federal Properties

Aptos: various unknown private landowners, Pacific Gas & Electric

has right-of-way

Freedom: Pajaro Unified School District (Aptos High School) and

private

1.2 Coordinate with agencies that have jurisdiction over these private

lands

With respect to project approval, the Branciforte parcel is under the

jurisdiction of the City of Santa Cruz; all the other private parcels are under

the jurisdiction of the County of Santa Cruz. In addition to these local

planning agencies, others parties that might be involved with recovery

activities could include the California Department of Fish and Game, the

California Native Plant Society, universities, botanic gardens and herbaria,

and other individuals knowledgeable about the plant and its habitat. Should

any projects be proposed for these sites, the agency with local jurisdiction 

should ensure that conservation measures are adequate to protect Chorizanthe
45

robusta var. robusta populations and habitat. We and the California

Department of Fish and Game should also be involved in reviewing project

proposals, and any mitigation plans and management plans developed in

association with the project.

1.3 Establish protection agreements and secure habitat sites with

permission of the landowners

Local agencies can solicit private landowner participation and support for

recovery, establish open space or conservation easements by the property

owner, establish permanent resource management easements, or acquire lands

through fee acquisition from willing sellers. Local lands trusts, such as the

Land Conservancy of Santa Cruz County, could assist with these efforts. The

Branciforte parcel is the highest priority for securing habitat protection

because the threats from development are imminent. The Rob Roy site is also

a high priority for securing habitat protection because it is vulnerable to

human impacts. The remaining private parcels are within more rural areas of

the County, and would be a lower priority for these efforts.

2. Manage habitat with existing Chorizanthe robusta var. robusta

populations

Chorizanthe robusta var. robusta populations and habitat on park and refuge lands

are either currently being managed, or management plans are being developed

currently (or, in the case of Buena Vista, in the near future). Populations and habitat

on private lands are the most vulnerable to human impacts, and are in the most need

of improved management. Populations on private lands include Baldwin Creek,

Branciforte, Freedom, and Aptos.

2.1 Eliminate or minimize threats on private lands

Threats identified to date are addressed below. Any additional threats should

be addressed as they are identified, or as additional populations are discovered

or established. As new threats become apparent, management actions should

be implemented to reduce or eliminate their effects on Chorizanthe robusta

var. robusta populations and habitat. 
46

Baldwin Creek: road maintenance 

Branciforte: trampling and other recreational impacts resulting from

use by local residents

Aptos: recreational use by local residents

Freedom: trampling and recreational impacts resulting from use by

high school students

2.2 Eliminate or minimize additional threats on parks and refuge lands

Any additional threats that arise on parks and refuge lands that have not been

addressed in management plans should be addressed as they arise. 

Management actions should be implemented that will reduce or eliminate

their effects on Chorizanthe robusta var. robusta. All management actions

should include monitoring for effectiveness, and future management should

be contingent on results of monitoring. 

3. Conduct management-oriented research

Research is needed to provide baseline information about the life history

characteristics and habitat characteristics of this variety of spineflower. This baseline

information will ensure that appropriate management actions are undertaken, and will

contribute to the long-term survival of this variety and its habitat. Also, baseline

information about life history and population characteristics will assist in developing

other appropriate recovery criteria.

3.1 Clarify the taxonomic identity of Chorizanthe robusta var. robusta

populations at known sites

The identity of Chorizanthe robusta var. robusta populations at known sites

should be clarified through biochemical or morphologic studies, by comparing

them to other populations of Chorizanthe in the Pungentes section in the

Monterey Bay and Point Reyes area. This is necessary to ensure that the

status of C. robusta var. robusta and other closely related spineflower taxa,

such as C. pungens var. pungens (Monterey spineflower), is appropriately
47

assessed. In addition, having this information will assure that the appropriate

spineflower taxon at each site is the correct target of recovery actions. 

3.2 Investigate life history and population characteristics

Identify Chorizanthe robusta var. robusta life history phases (e.g., seed

viability, seedling mortality, juvenile mortality, floral production, seed

production) and population characteristics which have the greatest effect on

population growth, species persistence, and the dynamics of populations

composed of several colonies.

3.3 Determine habitat characteristics important to the species

To some extent, the identification of physical and biological characteristics of

the habitat that are important to the establishment, growth, reproduction, and

the long-term persistence of Chorizanthe robusta var. robusta was initiated

during the process of designating critical habitat. However, C. robusta var.

robusta occurs in open patches within several other plant communities

(coastal sage scrub, maritime chaparral, oak woodland). Therefore, it is

important to do additional research to determine how the distribution of

shrubs within these communities influences the presence of C. robusta var.

robusta (patch dynamics) and how this taxon responds to different types and

intensities of disturbance within those communities.

3.4 Determine management actions that may be necessary to maintain

optimal habitat conditions for the species

As habitat conditions are better understood, management activities that

provide and maintain optimal conditions for Chorizanthe robusta var. robusta

need to be identified. This may include methods for maintaining the mosaic

of open patches within the shrub community (e.g., scraping, discing, fire

management, and/or selective removal of shrubs, small mammal

management), removal of nonnative species that compete with C. robusta var.

robusta, the use of grazing as a management tool, and eliminating or

minimizing human-caused disturbance of habitat.
48

3.5 Monitor each population at regular intervals

Monitoring the status of each population should be standardized to include

demographics, population trends, and potential threats. Population

monitoring protocol for the few large populations (e.g., Sunset State Beach,

Point Reyes National Seashore) may need to be tailored to focus on the areal

extent of occupied suitable habitat, while population monitoring for the

smaller populations can feasiblely focus on the number of individuals. The

data should be used to evaluate the status of Chorizanthe robusta var. robusta

and the success of any management actions that are being implemented. 

Management actions should be modified accordingly if changes in

management are needed.

4. Establish new Chorizanthe robusta var. robusta populations in

appropriate habitat within its historical range

Although additional populations of Chorizanthe robusta var. robusta have been

located in the last 5 years, the total number of populations is small. Moreover, with

the exception of the two populations at Point Reyes National Seashore, all of the

known populations of C. robusta var. robusta are concentrated in the Monterey Bay

area. Establishing new populations within the spineflower’s known historical range

would contribute to the long-term viability of the species. If new populations are

successfully established, it will reduce the likelihood that a catastrophic event could

result in the extinction of this taxon.

4.1 Locate appropriate habitat for outplanting

Habitat with physical characteristics and associated vegetation similar to

existing Chorizanthe robusta var. robusta habitat in the historical range of the

variety should be selected for outplanting sites. Surveys for appropriate sites

should include any historical locations that still support potentially suitable

habitat. Management of these new C. robusta var. robusta sites would be

facilitated by protected access, public/conservation group ownership, and/or

effective conservation easements. The Midpeninsula Regional Open Space

District owns and manages lands scattered throughout the San Francisco
49

Peninsula in San Mateo and Santa Clara Counties. These lands offer one of

the best opportunities to find suitable sites for outplanting new populations of

C. robusta var. robusta. We, the Midpeninsula Regional Open Space District,

and other interested organizations should assess whether any suitable

outplanting sites exist on Midpeninsula Regional Open Space District lands. 

Other potentially suitable sites in the Northern Santa Cruz and Aptos

geographic recovery units should also be identified

4.2 Conduct experimental habitat enhancement

Experimental habitat enhancement should be conducted in preparation for

new transplants of Chorizanthe robusta var. robusta. Habitat enhancement

may include scraping, raking, mowing, burning, selective removal of other

species, and reduction or elimination of human-caused disturbance if it is a

threat.

4.3 Apply appropriate habitat enhancement techniques

Based on results from habitat enhancement experiments, appropriate

techniques to enhance new habitat should be applied at the potential

introduction sites.

4.4 Conduct propagation experiments to determine the best techniques for

developing material to use in introductions

Propagation techniques need to be developed and a Chorizanthe robusta var.

robusta seed source produced from garden populations before trying to

conduct outplantings to establish new off-site populations. The first step in

off-site propagation is to determine feasibility by evaluating factors such as

seed viability, storage, germination, and survival in an experimental

environment.
50

4.5 Conduct experimental introductions

Chorizanthe robusta var. robusta seed from garden-propagated plants should

be transplanted to identified introduction sites. The transplants on these sites

should be monitored closely to determine the feasibility of expanding efforts

to establish populations through such introductions. 

4.6 Develop a protocol to guide introductions

A protocol should be developed to help guide efforts to introduce new

populations. The protocol should include such information as what type of

propagules to use, the type of post-planting care required, spacing

specifications, and optimal scheduling for planting activities.

4.7 Conduct large-scale introductions on appropriate sites

If experimental introductions appear to be successful, efforts should be

expanded to establish populations over larger areas and to more numerous

sites. 

4.8 Monitor newly established populations

Introduced populations should be mapped and monitored to determine longterm success of establishing new populations. Once established, both the

transplanted population of Chorizanthe robusta var. robusta and its habitat

should be monitored frequently and routinely.

5. Review and revise recovery criteria as new information becomes

available

Results of all recovery activities should be evaluated and incorporated into updated

management and recovery guidelines for the taxon. Expertise of the Center for Plant

Conservation should be utilized in assisting with these actions.

 
51

5.1 Redefine recovery criteria

When sufficient monitoring and research results become available, the

quantitative recovery criteria should be reviewed to determine if they are still

adequate and appropriate. Of particular importance to assess will be trends

indicated by population monitoring, and results of research into life history

and population dynamics (see recovery actions 3.2 and 3.5). In addition, if

results of a genetic taxonomic study determine that the numbers of

Chorizanthe robusta var. robusta populations are either fewer or greater than

our current understanding, recovery criteria for downlisting (which involve

establishing additional populations) most likely would have to be modified. If

criteria are not adequate or appropriate, they should be revised, incorporating

the new information. 

5.2 Update management and recovery guidelines

In accordance with adaptive management principles, the goals for recovery

and the ability to achieve them through management actions should be

revised, if monitoring and research indicate the need.

6. Develop and implement an outreach program

Increasing public awareness of Chorizanthe robusta var. robusta will facilitate efforts

to preserve it and its associated habitat. Brochures can be prepared and distributed at

the park and refuge units, and educational signs can be posted at appropriate locations

at these units. Educational materials should be provided to private landowners to

enlist their support in the conservation of C. robusta var. robusta, and to describe the

grant programs, such as the Partners for Fish and Wildlife Program, that are available

to assist them with habitat restoration efforts. 
52

IV. IMPLEMENTATION SCHEDULE

The table that follows is a summary of scheduled actions and costs for the

Chorizanthe robusta var. robusta recovery plan. It is a guide for meeting the

objectives discussed in Part II of this plan. The table includes the following five

elements, which are further discussed below: 1) the action priority; 2) the action

number and description; 3) the action duration; 4) lead agencies which are

responsible for performing the actions; and 5) cost estimates. 

1. Priority. The actions identified in the Implementation Schedule are those that, in

our opinion, should recover Chorizanthe robusta var. robusta. However, the actions

are subject to modification as dictated by new findings, changes in the status of the

taxon, and the completion of recovery actions. The priority for each action is given

in the first column of the implementation schedule. The priority number for each

recovery action is assigned one of the following levels:

Priority 1: An action that must be taken to prevent extinction or to prevent

the species from declining irreversibly in the foreseeable

future.

Priority 2: An action that must be taken to prevent a significant decline in

species population/habitat quality or some other significant

negative impact short of extinction.

Priority 3: All other actions necessary to provide for full recovery of the

taxon.

2. Action Number and Description. The action number and description are

extracted from the step down narrative found in Part III of the recovery plan. Please

refer back to this narrative for a fuller description of each action.
53

3. Action Duration. The Action Duration column indicates the number of years

estimated to complete the action if it is a discrete action, or whether it is a continual

or ongoing action. Continual and ongoing actions are defined as follows:

Cont = Continual. Action will be implemented on an annual basis once it has

begun.

Ong = Ongoing. Action is currently being implemented and will continue

until no longer necessary for recovery.

4. Responsible Parties. We have identified agencies and other parties that we

believe are primary stakeholders in the recovery process. The list of potential

stakeholders is not limited to the list below; other stakeholders are invited to

participate. For each action, the most logical lead agency (based on authorities,

mandates, and capabilities) has been identified as the responsible party with an

asterisk (*). For some actions, the responsible party essentially assumes all

responsibility for implementing the action; for other actions, the responsible party

may assume responsibility for coordinating other stakeholders as well. The following

abbreviations are used to identify primary stakeholders for each recovery action:

Acronyms for Responsible Agencies (* designates lead agency):

CDFG California Department of Fish and Game

CDPR California Department of Parks and Recreation

CPC Center for Plant Conservation

LCSC Land Conservancy of Santa Cruz County

MROSD Midpeninsula Regional Open Space District

NPS National Park Service (Point Reyes National Seashore)

PVT Private parties 

SCR City of Santa Cruz

SCCO Santa Cruz County

UC University of California or California State University

USFWS U.S. Fish and Wildlife Service
54

5. Cost Estimates. The estimated costs are shown for annual recovery actions

within a 7-year period. Total costs for ongoing and continuous actions are calculated 

based on the estimated 20-year timeframe to delisting. Numbers represent thousands

of dollars. The estimated costs include salaries for individuals who would carry out

each action. Typically, the responsible party (or lead agency) assumes the largest

share of the cost, with other stakeholders shown as contributors. Estimated costs in

this recovery plan do not commit any agency or party to an expenditure of funds. 

Therefore, initiation and completion of these actions is subject to the availability of

funds as well as other constraints affecting the stakeholders involved.
55

IMPLEMENTATION SCHEDULE FOR CHORIZANTHE ROBUSTA VAR. ROBUSTA RECOVERY 

PRIORITY

#

ACTION

#

ACTION DESCRIPTION DURATION

(YEARS)

RESPONSIBLE

PARTY

TOTAL

COST

($1000's)

YR1 YR2 YR3 

Need 1. Protect habitat with existing populations of Chorizanthe robusta var. robusta

2 1.1 Inform landowners 5 USFWS*

PVT

1 0.2 0.2 0.2 

2 1.2 Coordinate with jurisdictional

agencies

5 FWS*

SCCOSCRCDFGPVT

5 111

2 1.3 Establish protection agreements

or acquire habitat

5 SCCO

SCRLCSCPVT

TBD

Need 1 Subtotal Cost: $6,000 + TBD

+ Does not include cost of conservation easement or acquisition

Need 2. Manage habitat with existing populations of Chorizanthe robusta var. robusta

2 2.1 Eliminate, minimize threats on

private lands, with monitoring

Cont. SCCO

LCSCPVTCDFG

272020

0

4550

2550

2

2.52.5

0
IMPLEMENTATION SCHEDULE FOR CHORIZANTHE ROBUSTA VAR. ROBUSTA RECOVERY 

PRIORITY

#

ACTION

#

ACTION DESCRIPTION DURATION

(YEARS)

RESPONSIBLE

PARTY

TOTAL

COST

($1000's)

YR1 YR2 YR3 

56

2 2.2 Eliminate, minimize threats on

park and refuge lands, withmonitoring

Cont. CDPR

NPSUSFWSSCRCDFG

27101010

0

422

0.5

0

222

0.5

0

222

0.5

0

Need 2 Subtotal Cost: $124,000Need 3. Conduct management-oriented research2 3.1 Clarify taxonomic identity of

populations

2 USFWS*

NPSUC

15

3

 0

10

00

500

000

2 3.2 Investigate life history and

population characteristics

2 USFWS*

NPSUC

10

 5

 0

510

510

010

2 3.3 Determine habitat

characteristics

2 USFWS*

NPSUC

10

 5

 0

5

2.5

0

5

2.5

0

000

2 3.4 Determine management actions

to maintain optimal habitatconditions

2 USFWS*

NPSUC

2010

 0

000

000

10

 5 0

2 3.5 Monitor populations Cont. USFWS*

CDPRNPSSCR

102020

 10

0.5

11

0.5

0.5

11

0.5

0.5

11

0.5
IMPLEMENTATION SCHEDULE FOR CHORIZANTHE ROBUSTA VAR. ROBUSTA RECOVERY 

PRIORITY

#

ACTION

#

ACTION DESCRIPTION DURATION

(YEARS)

RESPONSIBLE

PARTY

TOTAL

COST

($1000's)

YR1 YR2 YR3 

57

Need 3 Subtotal Cost: $138,000Need 4. Establish populations within historical range2 4.1 Locate appropriate habitat for

outplanting

2 USFWS*

MOSD

10

5

00

00

5

2.5

2 4.2 Conduct experimental habitat

enhancement

2 USFWS*

MOSDUC

10

00

000

000

000

2 4.3 Apply appropriate habitat

enhancement techniques

2 USFWS*

MOSDUC

20

 0

00

00

00

2 4.4 Conduct propagation

experiments to developmaterial

2 USFWS*

CPCUC

10

 0

0

500

500

000

2 4.5 Conduct experimental

introductions

2 USFWS*

CPCUC

10

 0

0

000

000

000

2 4.6 Develop protocol to guide

introductions

2 USFWS*

CPCUC

500

000

000

000

2 4.7 Conduct large-scale

introductions

2 USFWS*

CPCUC

20

 0

0

000

000

000
IMPLEMENTATION SCHEDULE FOR CHORIZANTHE ROBUSTA VAR. ROBUSTA RECOVERY 

PRIORITY

#

ACTION

#

ACTION DESCRIPTION DURATION

(YEARS)

RESPONSIBLE

PARTY

TOTAL

COST

($1000's)

YR1 YR2 YR3 

58

2 4.8 Monitor newly established

populations

10 USFWS*

CPCUC

10

 0

0

000

000

000

Need 4 Subtotal Cost: $100,000Need 5. Review and revise recovery criteria as new information be comes available3 5.1 Redefine recovery criteria 1 USFWS*

NPSCDPRCPC

2000

0000

0000

0000

3 5.2 Update management and

recovery guidelines

1 USFWS*

NPSCDPRCPC

4000

0000

0000

0000

Need 5 Subtotal Cost: $6,000Need 6. Develop and implement an outreach program3 6 Outreach program 1 USFWS*

NPSCDPRSCR

0.50.50.50.5

0000

0000

0.50.50.50.5

Need 6 Subtotal Cost: $2,000TOTAL COSTS: $376,000 + TBD
V. REFERENCES

A. LITERATURE CITED

Baron, S. 1998. A demographic study of four annual plants of maritime chaparral. 

Senior thesis, University of California, Santa Cruz. 28 pages. 

Baron, S. 2002. Herbivory and an endangered plant, can a limited population handle

the pressure? Master of Science thesis, Department of Biology, San Jose

State University, California. 24 pages. 

Baskin, C. C., and J. M. Baskin. 1975. The seed bank in a population of an endemic

plant species and its ecological significance. Biol. Conserv. 14:125.

Baskin, C. C., and J. M. Baskin. 1998. Seeds: Ecology, biogeography, and

evolution of dormancy and germination. Academic Press, San Diego,

California. 850 pages.

City of Santa Cruz Recreation Department. 1998. Pogonip master plan. Santa Cruz,

California. Approx. 110 pages.

California Department of Parks and Recreation. 1998. Management plan, listed

species at Sunset State Beach. Santa Cruz Division, Santa Cruz, California.

California Department of Parks and Recreation. 2003. Natural history of

Chorizanthe robusta var robusta populations at Sunset State Beach. 3 pages

+ maps and aerial photos. Santa Cruz District, Santa Cruz, California.

California Natural Diversity Data Base. 1997. Unpublished records for Chorizanthe

robusta var. robusta. California Native Plant Society, Sacramento.

Ertter, B. 1990. Report on the results of a panel to evaluate the taxonomic validity of

Chorizanthe robusta var. hartwegii. Prepared for the U.S. Fish and Wildlife

Service, Ventura Fish and Wildlife Office, Ventura, California. 6 pages.

Ertter, B. 1996. Saga of the Santa Cruz spineflower. Fremontia 24:4. California

Native Plant Society, Sacramento, California.
60

Falk, D. A., and P. Olwell. 1992. Scientific and policy considerations in restoration

and reintroduction of endangered species. Rhodora 94(879):287-315. 

Fiedler, P. L. 1991. Mitigation-related transplantation, relocation and reintroduction

projects involving endangered and threatened, and rare plant species in

California. Report prepared for California Department of Fish and Game,

Sacramento. Contract No. FG-8611.

Given, D. 1994. Principles and practice of plant conservation. Timber Press,

Portland, Oregon. 292 pages.

Habitat Restoration Group. 1996. Pogonip biotic assessment. Prepared for the City

of Santa Cruz.

Hickman, J. C. 1993. Chorizanthe. Pages 856-860 in: J. C. Hickman (Ed.). The

Jepson manual - higher plants of California. University of California Press. 

Hyland, T. 2003. Preliminary status report for Chorizanthe robusta v. robusta,

robust spineflower. California Department of Parks and Recreation, Santa

Cruz. Division, Santa Cruz, California.

Jepson, W. L. 1913. A flora of California. Polygonaceae. p 392.

John Gilchrist and Associates. 1986. Draft Pogonip biotic study. Prepared for the

Pogonip Advisory Committee.

McGraw, J. M., and A. L. Levin. 1998. The roles of soil type and shade intolerance

in limiting the distribution of the edaphic endemic Chorizanthe pungens var

hartwegiana (Polygonaceae). Madrono, Vol. 45, No. 2:119-127.

Moldenke, A. 1976. California pollination ecology and vegetation types. 

Phytologia, 34:305-361.

Morgan, R., and L. Kiguchi. 1995. Biotic assessment and management plan for

Russian Heights, Inc., Aptos, California. 14 pages and appendices.
61

Murphy, A. 2003. Endangered plant conservation: do pollinators matter to the robust

spineflower? Masters Thesis, Department of Environmental Studies, San

Jose State University, San Jose, California. 

National Park Service. 1980. General management plan environmental analysis for

Point Reyes National Seashore. National Park Service, San Francisco

Regional Office, California.

National Park Service. 1985. The National Park Service statement for management. 

Washington D.C.

National Park Service. 1991. Guidelines for natural resources management. 

Washington D.C.

Parry, C. C. 1889. Chorizanthe, R. Brown. Review of certain species heretofore

improperly characterized or wrongly referred; with two new species. Proc.

Davenport Academy of Natural Sciences 5: 174-184.

Reveal, J. L., and C. B. Hardham. 1989. A revision of the annual species of the

Chorizanthe (Polygonaceae: Eriogonoideae). Phytologia 66: 98-198.

Reveal, J. L., and R. Morgan. 1989. A new combination in Chorizanthe robusta C.

Parry (Polygonaceae: Eriogonoideae) from California. Phytologia 67(5): 357-

360.

Reveal, J. L. 2001. Scientific review questions on Chorizanthe parryi S. Watson var.

fernandina (S. Watson) Jepson (San Fernando Valley spineflower). 

University of Maryland, College Park, Maryland.

Santa Cruz County. 1994. Local Coastal Program and General Plan. Santa Cruz,

California.

State Park and Recreation Commission. 1994. Statements of Policy. Sacramento,

California.
62

U.S. Fish and Wildlife Service. 1983. Endangered and threatened species: Listing

and recovery priority guidelines. Federal Register 48:43098-43105. 

September 21, 1983.

U.S. Fish and Wildlife Service. 1994. Endangered and threatened wildlife and

plants: Endangered status for three plants and threatened status for one plant

from sandy and sedimentary soils of central and coastal California. Federal

Register 59:5499-5511. February 4, 1994.

U.S. Fish and Wildlife Service. 1998a. Recovery plan for seven coastal plants and

the Myrtle’s silverspot butterfly - northern and central California, Humboldt

County south to Santa Barbara County. Portland, Oregon. 117 pages.

U. S. Fish and Wildlife Service. 1998b. Preliminary project proposal: proposed

addition of the Calabasas and Buena Vista properties to the Ellicott Slough

National Wildlife Refuge. Portland, Oregon. 9 pages + appendices. 

U.S. Fish and Wildlife Service. 1999. Recovery Plan for insect and plant taxa from

the Santa Cruz Mountains in California. Portland, Oregon. 83 pages.

U.S. Fish and Wildlife Service. 2000a. Draft recovery plan for the robust

spineflower (Chorizanthe robusta var. robusta). Portland, Oregon. 40 pages.

U.S. Fish and Wildlife Service. 2000b. Availability of a draft recovery plan for the

robust spineflower (Chorizanthe robusta var. robusta) from Santa Cruz

County, California. Federal Register 65:56590. September 19, 2000.

U. S. Fish and Wildlife Service. 2002. Critical habitat designation for Chorizanthe

robusta var. robusta (robust spineflower). Federal Register 67:36822-36845.

May 28, 2002. 

U.S. Fish and Wildlife Service. 2003. Draft conceptual management plan for

proposed Ellicott Slough National Wildlife Refuge addition, Santa Cruz

County, California. San Francisco Bay National Wildlife Refuge Complex,

Newark, California. 8 pages + maps.
63

Van Dyke, E., and K. Holl. 2003. Mapping the Distribution of Maritime Chaparral

Species in the Monterey Bay Area. Prepared for the U.S. Fish and Wildlife

Service, Ventura Fish and Wildlife Office, Ventura, California. 8 pages +

figures. 

Zedler, P. H., and C. Black. 1989. Observations on the creation of artificial habitat

for species preservation. From: Workshop proceedings on restoration and

creation of vernal pools. California Department of Fish and Game,

Sacramento. February 14-15, 1989.

B. IN LITT. REFERENCES

Baron, Sandy. 1995. Letter regarding the identity of spineflower observed on the

Buena Vista parcel. Sent to U.S. Fish and Wildlife Service, Ventura Fish and

Wildlife Office, Ventura, California.

Baron, Sandy. 1998. E-mail sent to Connie Rutherford, USFWS botanist, regarding

the Buena Vista property and Chorizanthe robusta var robusta. Dated

January 6, 1998.

Baron, Sandy. 1999a. Chorizanthe robusta var. robusta survey at Pogonip, City of

Santa Cruz, July 1, 1999. Sent to U.S. Fish and Wildlife Service, Ventura

Fish and Wildlife Office, Ventura, California. 2 pages.

Baron, Sandy. 1999b. Chorizanthe robusta var. robusta at the Buena Vista site,

5/15/99 - 5/27/99. 2 pages.

Baron, Sandy. 2000. Letter to U.S. Fish and Wildlife Service, Ventura Fish and

Wildlife Office, Ventura, California, regarding review of the draft recovery

plan for the robust spineflower. Letter dated October 20, 2000. 

Baron, Sandy. 2003. E-mail regarding the status of the robust spineflower

population at Buena Vista. Received by Connie Rutherford, U.S. Fish and

Wildlife Service, Ventura Fish and Wildlife Office, Ventura, California.

Dated May 4, 2003.
64

Brown, Sandy. 2003. Letter to Brad Bowman, First Federal Properties from the City

of Santa Cruz Planning Department, regarding damage to robust spineflower

population on the Market and Isbel property and the need to restore the site.

Dated May 7, 2003.

Cheap, Vince. 2001. Letter to Bruce Beck, California Department of Forestry,

regarding the location of robust spineflower during surveys adjacent to Aptos

High School. U.S. Fish and Wildlife Service files, Ventura Fish and Wildlife

Office, Ventura, California. Dated June 1, 2001.

Coppoletta, Michelle. 2003. E-mail regarding the status of robust spineflower

populations at Point Reyes National Seashore. Sent to Connie Rutherford,

U.S. Fish and Wildlife Service, Ventura Fish and Wildlife Office, Ventura,

California. Dated May 6, 2003.

Ertter, Barbara. 1997. Revised key to the Chorizanthe in the Pungentes section. 

Sent via e-mail to U.S. Fish and Wildlife Service, Ventura Fish and Wildlife

Office, Ventura, California. 

Ertter, Barbara. 2001. Letter to Wilma Follette regarding the identity of spineflower

collected at Point Reyes National Seashore. Letter dated January 22, 2001.

Gray, George. 2000. Letter with review comments on the draft recovery plan for

robust spineflower. Sent to U.S. Fish and Wildlife Service, Ventura Fish and

Wildlife Office, Ventura, California. Dated November 21, 2000.

Grumbine, Ed. 2003. E-mail regarding the status of the robust spineflower

population at Baldwin Creek. Received by by Connie Rutherford, U.S. Fish

and Wildlife Service, Ventura Fish and Wildlife Office, Ventura, California.

Dated May 7, 2003.

Kiguchi, Laurie. 2000. Letter to U.S. Fish and Wildlife Service, Ventura Fish and

Wildlife Office, Ventura, California, regarding review of the draft recovery

plan for the robust spineflower. Letter dated November 20, 2000.
65

Lyons, Kathy. 2001. Letter to U.S. Fish and Wildlife Service, Ventura Fish and

Wildlife Office, Ventura, California, regarding review of the draft recovery

plan for the robust spineflower. Letter dated November 16, 2001.

Murphy, Annie. 2001. Notes on pollinators of robust spineflower at Sunset State

Beach. Sent to the U.S. Fish and Wildlife Service Ventura Fish and Wildlife

Office, Ventura, California. 1 p.

Rodgers, Jane. 2003. FAX regarding the status of robust spineflower populations at

Point Reyes National Seashore. Sent to Connie Rutherford, U.S. Fish and

Wildlife Service, Ventura Fish and Wildlife Office, Ventura, California. 

Dated April 24, 2003.

Taylor, Dean. 2000. California Natural Diversity Data Base Field survey form for

Chorizanthe robusta var. robusta from PG&E right of way near Aptos, Santa

Cruz County, California.

C. PERSONAL COMMUNICATIONS

Bill Davilla. 1998. Ecosystems West, Ben Lomond, California. Conversation with

Connie Rutherford, USFWS botanist, regarding the identity of spineflower

populations located in the Rob Roy Junction area and Buena Vista.

Randy Morgan. 2000. Biologist, Santa Cruz, California. Conversation with Connie

Rutherford, USFWS botanist, regarding a new population of robust

spineflower that was found on the Branciforte parcel (Market x Isbel) in the

City of Santa Cruz.

Witthaus, Rob. 2003. Biologist, Pacific Gas & Electric Company. Conversation

with Connie Rutherford, USFWS botanist, regarding human activities along

the PG&E corridor in the Aptos area.
66

VI. APPENDICES

APPENDIX A. Explanation of Recovery Priority System

The Recovery Priority System uses the criteria of degree of threat, recovery potential, and taxonomy

(level of genetic distinctiveness) to assign all listed species a number (1-18). A fourth factor, conflict,

is a supplementary element that gives priority, within each category, in preparation of recovery plans to

species that are, or may be in conflict with construction or development projects. Thus, the species

retains its numerical rank and acquires the letter designation of “C”, indicating conflict (1C-18C). The

Recovery Priority System is discussed in detail in U.S. Fish and Wildlife Service (1983).

 Degree

of

Threat

Recovery

Potential Taxonomy Priority Conflict

 High

High

High

High

Low

Low

Low

Monotypic genus

Species

Subspecies

Monotypic genus

Species

Subspecies

1

2

3

4

5

6

 1C

1

 2C

 2

3C

 3

4C

4

5C

5

6C

6 

 Moderate

High

High

High

Low

Low

Low

Monotypic genus

Species

Subspecies

Monotypic genus

Species

Subspecies

7

8

9

10

11

12

7C

7

8C

8

9C

9

10C

10

11C

11

12C

12

 Low

High

High

High

Low

Low

Low

Monotypic genus

Species

Subspecies

Monotypic genus

Species

Subspecies

13

14

15

16

17

18

13C

13

14C

14

15C

15

16C

16

17C

17

18C

18
67

APPENDIX B: Historical collections of Chorizanthe robusta var. robusta. 

Population ID#1

and location2

Collector

& Date

Ownership Status3 and Comments

1. Alameda AC Bolander 1866; Greene

1891 

- extirpated

2. Colma SMC Brandegee 1905; 

Suksdorf 1913

- extirpated

3. Felton SCC Thompson 1913 - extirpated

4. Los Gatos SCLC Leeds 1888 - extirpated

5. north of Santa Cruz

(Paul Sweet Rd.) SCC

Morgan 1977 private unknown. Population

has not been relocated

6. Pogonip Park, s of

Brayshaw Trail SCC

Morgan 1986 City of Santa Cruz extant

7. Pogonip Park, w of

Nature Loop Trail, SCC

Morgan 1986 City of Santa Cruz extant

8. Rodeo Gulch Road,

Soquel, SCC

Hesse 1960

(also Belshaw 1936)

private unknown. Potential

sighting in 2000 needs to

be checked

9. Manresa State Beach,

SCC

Raven 1957

Morgan 1979

Calif. Dept of Parks

& Recreation

extant

10. Sunset State Beach,

SCC

Reveal & Broome 1987;

Morgan 1988

Calif. Dept. of Parks

& Recreation

extant

11. 1.5 mi. east of

Watsonville Junction, MC

Belshaw 1936 - extirpated 4

12. Del Monte, MC Elmer 1902 - extirpated 4

13. 1 mi. south of San

Lucas, MC

Keck & Stockwell 1935 - extirpated 4

14. S end of Sunset State

Beach, SCC

1985 Calif Dept. of Parks

& Recreation

extirpated

15. East of Manresa State

Beach (Buena Vista), SCC

Lake 1993 Calif. Dept. of Fish

and Game, U.S.

Fish and Wildlife

Service

extant

16. NE of Rob Roy

Junction, SCC

Morgan 1993 Aptos School

District/ private

extant

(no #) Santa Cruz, SCC Jones 1881 - corresponds to Pogonip

pops?

18. Ocean View District

of San Francisco, SFC

Congdon 1889 - extirpated
68

19. San Jose, SCLC Parry 1882 - extirpated

20. near Soledad, MC Congdon 1881 - unknown 5

21. 4 mi from Moss

Landing on Pojano

[Pajaro] Road, MC

Abrams 1903 - extirpated 5

22. Salinas Valley near

Monterey Bay, MC

Abbott 1889 - extirpated 5

1

Identification # corresponds to that used in the California Natural Diversity Data Base (CNDDB)

2

 County codes are as follows: AC =Alameda County, MC =Monterey County, SCC = Santa Cruz County, SCLC = Santa

Clara County, SMC = San Mateo County, SFC = San Francisco County.

3 Populations identified as “extirpated” are presumed extirpated by the Service; this opinion may differ from that of

CNDDB.

4

 Barbara Ertter noted that specimen is intermediate in characteristics between Monterey spineflower (Chorizanthe

pungens var pungens) and robust spineflower (Chorizanthe robusta var robusta).

5

Barbara Ertter noted that specimen is closer in characteristics to Monterey spineflower (Chorizanthe pungens var

pungens) than robust spineflower (Chorizanthe robusta var robusta). 
69

APPENDIX C: Summary of Agency, Peer, and Public comments on the Draft

Recovery Plan

In September 2000 we released the Draft Recovery Plan for the Robust Spineflower (U.S.

Fish and Wildlife Service 2000a) for a 60-day comment period that ended on November 20,

2000, for all interested agencies and members of the public (U.S. Fish and Wildlife Service

2000b). 

In response to the release of the draft plan, we received six letters, each containing varying

numbers of comments. Copies of the draft recovery plan were sent to approximately 65

interested parties. Of these, three individuals (Kathy Lyons, Joe Rigney, and Laurie

Kiguchi), were asked to peer review the document; all three peer reviewers responded. Peer

reviewers were selected for their familiarity with the taxonomic group, a geographic area,

and/or jurisdictional issues.

The number of parties responding, by affiliation:

State agencies 1

Academia/professionals 5

Summary of Significant Comments and Our Responses

We reviewed all of the comments received during the comment period. Comments that

were editorial or technical in nature, or were updating the information in the draft recovery

plan, have been incorporated into the appropriate sections of the recovery plan. We did not

receive any comments that we considered controversial or significant in the sense of making

a difference in the fundamental way that recovery of Chorizanthe robusta var. robusta is

being approached.

Comment: Several commenters suggested that more discussion should be included

regarding the need to manage vegetation to benefit Chorizanthe robusta var.

robusta. Two types of needed management were identified: management of

native shrubs that are shading out C. robusta var. robusta, and management

of invasive, nonnative species that may outcompete C. robusta var. robusta.

Response: We agree, and have added additional discussion of vegetation management to

the document.

Comment: Several commenters asked that additional discussion regarding the role of

disturbance in maintaining habitat for Chorizanthe robusta var. robusta be

included in the plan.

Response: We agree, and have added additional discussion to the section entitled

Habitat Description and Critical Habitat.
70

Comment: One commenter stated that regional planning efforts are needed, and that

through the plan, we should be encouraging the County of Santa Cruz to

develop a regional Habitat Conservation Plan that would include landowner

incentives for preservation and management of habitat.

Response: We agree that regional planning efforts could contribute to the recovery of

this as well as other species in the County. We have discussed the concept of

initiating a county-wide or smaller regional scale Habitat Conservation Plan

effort with the County Planning Department. However, the County is unable

and unwilling to do so at this time.
71

APPENDIX D: Threats identified for Chorizanthe robusta var. robusta and Recovery

Plan Recommended Management Actions

Threat (Listing Factor) Recovery Actions (Action #) Recovery

Criteria

Habitat destruction from

development, recreation,

other human activities (A)

Eliminate, minimize threats on private lands, with

monitoring (2.1); Eliminate, minimize threats on park

and refuge lands, with monitoring (2.2); Monitor

populations (3.5)

1, 2, 3

Habitat alteration due to

competition with nonnative

species (A, E)

Investigate life history and population characteristics

(3.2); Determine habitat characteristics (3.3);

Determine management actions to maintain optimal

habitat conditions (3.4); Monitor populations (3.5)

1, 2, 3

Habitat alteration due to

shading by shrub overstory

(A, E) 

Investigate life history and population characteristics

(3.2); Determine habitat characteristics (3.3);

Determine management actions to maintain optimal

habitat conditions (3.4); Monitor populations (3.5)

1, 2, 3

Predation by insects, small

mammals (Factor C)

Determine management actions to maintain optimal

habitat conditions (3.4); Monitor populations (3.5)

1

Grazing by cattle (Factor C) Eliminate, minimize threats on park and refuge lands,

with monitoring (2.2); Monitor populations (3.5)

1

Inadequate regulatory

mechanisms (Factor D)

Inform landowners (1.1); Coordinate with

jurisdictional agencies (1.2); Establish protection

agreements or acquire habitat (1.3); Outreach program

(6.0)

1, 2, 3

Small population size,

stochasticity (E)

Clarify taxonomic identity of populations (3.1); Locate

appropriate habitat for outplanting (4.1); Conduct

experimental habitat enhancement (4.2); Apply

appropriate habitat enhancement techniques (4.3);

Conduct propagation experiments to develop material

(4.4); Conduct experimental introductions (4.5);

Develop protocol to guide introductions (4.6); Conduct

large-scale introductions (4.7); Monitor newly

established populations (4.8); Redefine recovery

criteria (5.1); Update management and recovery

guidelines (5.2)

1, 2, 3