United States

Department of

Agriculture

Forest Service

Pacific Northwest

Research Station

General Technical

Report

PNW-GTR-571

February 2003

Horse Rock Ridge Research 

Natural Area

Guidebook Supplement 27

Alan B. Curtis
Alan B. Curtis is a forester and botanist retired from the U.S. Department of the 

Interior, Bureau of Land Management, Eugene District, P.O. Box 10226, Eugene, OR 

97440-2226. Printing of this document was partly funded by the Pacific Northwest 

Research Station.

Author
Curtis, Alan B. 2003. Horse Rock Ridge Research Natural Area: guidebook 

supplement 27. Gen. Tech. Rep. PNW-GTR-571. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 30 p.

Horse Rock Ridge Research Natural Area (HRR RNA) was established in June 

1995 to protect the best remaining example of a grassy “bald” (treeless area) 

on the western margin of the Cascade Range and its associated botanical, 

wildlife, and scenic values. This bald is surrounded by old-growth Pseudotsuga 

menziesii/Tsuga heterophylla (Douglas-fir/western hemlock) forest in the Coburg 

Hills on the eastern edge of the Willamette Valley in western Oregon. The site 

is recognized for its considerable diversity of plant species that includes both 

Willamette Valley plants as well as plants more often found in the montane zone 

of the Cascade Range. There are also several species present at the site that 

are normally found east of the Cascade Range. This guidebook describes the 

area, environment, biota, disturbance history, research, and access.

Keywords: Research natural area, vegetation types, vascular plants, lichens, 

liverworts, mosses, birds, mammals, mollusks, amphibians, reptiles. 

Abstract
blank
1

Horse Rock Ridge Research Natural Area (HRR RNA) was established in June 1995 

to protect the best remaining example of a grassy “bald” (treeless area) on the western margin of the Cascade Range and its associated botanical, wildlife, and scenic 

values (fig. 1). The bald is surrounded by old-growth Pseudotsuga menziesii/Tsuga 

heterophylla forest in the Coburg Hills on the eastern edge of the Willamette Valley 

in western Oregon. The site is recognized for its considerable diversity of plant species that includes both Willamette Valley plants as well as plants more often found in 

the montane zone of the Cascade Range (Oregon Natural Heritage Advisory Council 

1993).1 There are also several species present at the site that are normally found east 

of the Cascade Range. 

There are two primary communities at this RNA—grassland and forest. Within each 

of these communities, there are a number of plant associations:

• Grasslands occupy the open, south-facing slopes at HRR, usually occurring 

in areas with soils shallower than the soil in forested areas. The grassland 

community consists of three distinct plant associations: Elymus glaucus (blue 

wildrye) association; Festuca idahoensis (Idaho fescue) association; and Stipa 

lemmonii/Racomitrium canescens (Lemmon’s needlegrass/moss) associations. 

• The forest community is classed as a Pseudotsuga menziesii/Tsuga heterophylla

(Douglas-fir/western hemlock) association with an understory dominated by 

small Berberis nervosa (Cascade Oregongrape), Gaultheria shallon (salal), and 

Symphoricarpos albus (snowberry). The forest occurs on the deepest soils within 

the natural area (Vander Schaaf 1993).

This 153-ha (378-acre) area is located in Linn County, Oregon (fig. 2), and is administered by the McKenzie Resource Area of the Eugene District, Bureau of Land 

Management (BLM). The RNA is situated in section 1, T. 15 S., R. 2 W., Willamette 

Meridian (44°18′ N. latitude and 122°52′ W. longitude). 

To reach the RNA, take U.S. Interstate 5 to Springfield exit 194A. Drive east on Interstate 105 (Oregon state Highway 126) 4.0 mi (6.4 km) to the Marcola exit. Travel north 

on Marcola Road 0.9 mi (1.4 km), cross the McKenzie River, drive 9.8 mi (15.8 km) to 

the town of Marcola, and continue northward 3.4 mi (5.5 km) to Shotgun Creek Road 

BLM 16-1-5. Turn onto this road and drive 3.5 mi (5.6 km) to the Seeley Creek Road 

BLM 15-1-19.1. Turn onto this road and drive 2.5 mi (4.0 km) and continue on BLM 

road 15-1-18.2 for 1.5 mi (2.4 km) to a gravel stockpile on the west side of the road. All 

roads to this point are paved. Park here and proceed on foot northward along the main 

road 0.1 mi (0.2 km) to BLM road 15-2-1 (closed to all vehicles) and follow it through 

young timber for 0.6 mi (1.0 km) to the open grasslands. 

Or, take Interstate 5 to the Brownsville exit 216. Drive east on Oregon state Highway 

228 to Crawfordsville. Just east of this town, turn south on Brush Creek County Road 

1900 and drive 2.0 mi (3.2 km) to its intersection with West Fork Brush Creek Road, 

BLM 14-1-32. Turn onto this road and drive 2.5 mi (4.0 km) and continue on BLM road 

15-1-18.2 for 1.0 mi (1.6 km) to a gravel stockpile on the west side of the road. All 

roads to this point are paved. Park here and proceed on foot northward along the main 

road 0.1 mi (0.2 km) to BLM road 15-2-1 (closed to all vehicles) and follow it through 

young timber for 0.6 mi (1.0 km) to the open grasslands. 

1 See appendix for species list.

Access and 

Accommodations

Introduction
2 

Commercial accommodations are available in the Springfield-Eugene metropolitan 

area and in Brownsville. Commercial air, rail, and bus service is available in Eugene. 

Horse Rock Ridge RNA is located in the Coburg Hills on the divide between the Calapooya and Mohawk River drainages in western Oregon. It lies east of the Willamette 

Valley and is part of the western slope of the Cascade Range physiographic province. 

Approximately two-thirds of the RNA has a southern exposure, and the rest of the 

area lies on a north slope. The topography is rugged with rock outcroppings and steep 

slopes. The RNA consists of a mosaic of open grasslands, young-growth forest (on 

areas previously logged), and old-growth forest. The elevation of the RNA ranges from 

472 to 873 m (1,550 to 2,864 ft). 

The Pacific Ocean, 61 mi (98 km) west of the RNA, gives the area a temperate marine 

climate—cool, wet winters and warm, dry summers. The RNA lies nearly equidistant 

between the weather stations at the Eugene airport (to the southwest) and at Foster 

Dam (to the northeast). Both stations are at elevations much lower than the RNA, with 

the Eugene airport at an elevation of 109 m (359 ft). Yearly mean precipitation recorded at the Eugene airport for the years 1961 through 1990 was 194 cm (49 in), and 

at Foster Dam was 209 cm (53 in) (Oregon State University 2001). As the elevation of 

the RNA is some 600 m (2,000 ft) higher than these two weather stations, precipitation is likely to be considerably more at the RNA. About 70 percent of the precipitation 

falls from November through March, and only 5 percent from June through August. 

Most of this is rain, although snow may cover the ground for a few days to a couple 

of weeks or, rarely, more each year. 

Figure 1—View northwest toward the summit of Horse Rock Ridge Research Natural Area showing open, 

south-facing slopes.

Environment
3

Figure 2—Horse Rock Ridge Research Natural Area.
4 

At the Eugene airport, temperatures average 3.8 °C (40 °F) in January and 19.4 °C 

(67 °F) in July, and the mean annual temperature is 11.1 °C (52 °F). The mean annual 

temperature at Foster Dam is the same as at the Eugene airport. In summer, the 

relative humidity at Eugene is usually between 35 and 50 percent, but it occasionally 

drops below 30 percent. Evaporation at this time far exceeds precipitation and leads 

to drought. 

Stable high-pressure summer airmasses bring clear skies and light winds from the 

north. In summer and fall, temperature inversions sometimes occur in the Willamette 

Valley and adjacent areas. In late fall, winter, and spring, unstable low-pressure airmasses bring frequent storms from the Pacific Ocean. Prevailing winds are out of the 

southwest, and their force sometimes causes extensive windthrow of trees. Windspeeds of 63 mi per hour (101 km per hour) were recorded at the Eugene airport during the Columbus Day storm in 1962. Large trees that were wind-thrown by this storm 

can still be seen along the forest/grassland interface in the RNA (fig. 3).

The predominant bedrock at HRR is a series of basalt and basaltic andesite flows. 

These volcanic rocks were deposited during the Oligocene and early Miocene epochs 

about 24 million years ago. The rocks are extrusive, formed by rapid cooling of molten 

lava at the surface. The rocks found at HRR have a prevalent “amygdaloidal texture.” 

When the lava flows cooled, dissolved gasses in the molten rock were trapped in 

cavities called vesicles. These voids in the rock were filled with other minerals that 

precipitated from water circulating in the rock just before, or at some time after, consolidation. These other minerals that filled the voids are known as amygdales. At 

HRR the amygdales are zeolites and quartz, white in color, and round in shape. As 

the basaltic rocks erode, the zeolite and quartz amygdales break off, and small specimens can be found on the surface of the rock outcrops throughout the area. 

Sometime after the lava flows were formed, a nearly vertical crack, or series of cracks 

developed. The fissure cut steeply across the older flow layers and filled with molten 

lava to form a dike. This dike is a prominent outcropping of fine-grained basalt that was 

fractured during the natural cooling process. Owing to its fine-grained texture, the dike 

is more resistant to erosion, as compared to the amygdaloidal basalt flows. Sections 

of the dike consist of horizontal columnar jointing. The dike, which is more than 100 

meters long, is clearly visible in the grasslands area of the RNA (fig. 4). 

Soils in the grassland areas are a complex of rock outcrop (60 percent) and Entisols 

(30 percent). Slopes are typically 55 to 70 percent. These soils exhibit little or no development. Entisols typically occur on young landscapes where the soil material has 

not been in place long enough for soil processes to form diagnostic horizons (fig. 5). 

This is the case at HRR where the basalt is very resistant and slopes are steep and 

actively eroding. Horizontal orientation of the basalt flows also may contribute to the 

fact that water is readily shed from the site as runoff and is not available for soil formation. Soils here are generally well drained and have loamy or sandy loam textures. 

Depth is highly variable: 18 cm near exposed bedrock, 36 cm in depositional areas 

Soils3

Geology2

2 Ward, K.; Wiedenbeck, R.; Baitis, K. 2001. Personal communication. Hydrologist, and soil scientists, respectively. USDI Bureau 

of Land Management, P.O. Box 10226, Eugene, OR 97440-2226.

3 References used: USDA NRCS 1999, USDA SCS 1987.
5

Figure 4—The basaltic dike extends from the ridgetop in a southeast direction for 

more than 100 meters down the slope.

Figure 3—Herbaceous plants cover the steep south-facing 

slopes of the research natural area. The row of wind-thrown 

trees at the base of the slope dates from a 1962 windstorm.
6 

near drainages, and as deep as 91 cm on the less severe slopes along the main 

ridgeline where some old-growth Pseudotsuga menziesii occurs. Content of gravel 

and cobble also differs greatly. 

Soils in forested portions of the RNA are primarily the Kinney series. These soils are 

deep and well drained. They formed in colluvium derived dominantly from undifferentiated tuffaceous rock. The soil surface is a cobbly loam about 38 cm thick. The subsoil 

is a cobbly clay loam about 51 cm thick. Average depth to bedrock is 1.4 m. Many 

slope phases of Kinney soils are mapped within the RNA, with the largest area occurring on steep (50 to 70 percent) upper slopes. Lower slopes are more moderate (20 to 

50 percent). Kinney is a very productive forest soil. Site index is 180 for Pseudotsuga 

menziesii and 140 for Tsuga heterophylla, based on height growth over 100 years.

There are several small (roughly 1⁄2- to 1-m square) seasonal springs near the ridgetop 

in the RNA. Although they dry up completely in summer, they support small populations of wetland plants and flow during storm events. Many ephemeral stream channels are found on the lower reaches of the grasslands. These are eroded to bedrock 

owing to the thin, fragile soil found there, and the channels are typically about 30 cm 

across (fig. 6). 

Lower slopes in the RNA are dissected by several stream channels, but they flow 

only during late fall, winter, and spring when storms bring adequate moisture from the 

Pacific Ocean.

Horse Rock Ridge RNA is noted for its diversity of plant communities and species. 

The checklist of vascular plants for the site includes more than 230 species. None of 

the plants at this site are federally listed as threatened or endangered. 

Hydrology 4

Vegetation

Figure 5—View of basaltic outcrops and shallow Entisols soils. 

4 Ward, K.; Wiedenbeck, R. 2001. Personal communication. 

Hydrologist and soil scientist, respectively. USDI Bureau of Land 

Management, P.O. Box 10226, Eugene, OR 97440-2226.
7

Figure 6—Dry ephemeral stream channel on the upper slope of the research natural 

area, August 2001. 

Figure 7—View southeast from the upper slopes of the research natural area.
8 

The grass bald at this RNA is one of the largest on the western slope of the Cascade 

Range and covers 34 ha (83 acres). Outstanding areas of undisturbed grassland 

occupy south-facing slopes where there has been no grazing by domestic animals 

for many decades. The upper slopes receive intense solar radiation and dry out by 

midsummer (fig. 7). 

The grasslands at HRR contain a greater diversity of species than other similar sites 

on the western slope of the Cascade Range. Many wildflowers are found here, including Blepharipappus scaber and Balsamorhiza deltoidea, which are more typical 

of central and eastern Oregon grasslands. 

Within the grassland community, there exists a mosaic of plant associations.

The Festuca idahoensis association is notable as it is unusual in western Oregon 

although it is common in arid areas of eastern Oregon and throughout the intermountain West. This association occupies the deepest soils in the grasslands area of the 

RNA. These sites are often concave and appear to be moister than surrounding areas. 

The soils may comprise considerable colluvium that has resulted from upslope slumping and soil creep. This association is less weedy and occupies less overall area than 

the Elymus glaucus association. 

The Elymus glaucus association is the most prominent on the grasslands at HRR. It 

occurs on convex slopes with moderate soil depths. This association typifies grassy 

balds on the western slope of the Cascade Range and higher elevations of the Willamette Valley that have not been lost through heavy livestock grazing and invasion by 

weedy annual grasses and aggressive exotic plants.

The Stipa lemmonii/Racomitrium canescens association occurs on slopes over a 

gravel substrate where there is little or no appreciable soil formation. There are fewer 

weeds found here as compared to the other grassland associations noted above. A 

variant of this association is found directly on rock outcrops where Eriogonum nudum

is prominent in small sites. 

There are a few vernal seeps below the ridgeline on the south slope of the RNA. Within the immediate vicinity of the seeps are areas dominated by algal mats and Carex 

rossii with Mimulus guttatus of common occurrence. Juncus kelloggii also grows there, 

a species rare in Oregon. This Mimulus-Juncus association has surface water present 

during part of the growing season. 

The forest area at this RNA surrounds the grassland community (fig. 8). Common 

shrubs that occur in the transition area are Arctostaphylos columbiana, Rhus diversiloba, Holodiscus discolor, and Amelanchier alnifolia. Scattered trees occurring in the 

transition area include Arbutus menziesii and Quercus garryana.

The forest community is part of the Pseudotsuga menziesii/Tsuga heterophylla association with an understory dominated by several species of shrubs including Berberis 

nervosa, Gaultheria shallon, and Symphoricarpos albus (Franklin and Dyrness 1973). 

This old-growth forest is found on the deepest soils, located mostly along the ridgetop, 

on the northern and eastern faces of the RNA, and along the lower slopes of the site 

on the south side. 

The Pseudotsuga menziesii/Tsuga heterophylla association covers 50 ha (124 acres) 

and is found on north- and northeast-facing slopes, whereas on other exposures, the 

old-growth forest is mainly composed of Pseudotsuga menziesii and covers 30 ha (64 

Forest

Grasslands
9

Figure 8—Aerial photo showing the mosaic of grasslands and forests of Horse Rock Ridge Research 

Natural Area. 

acres). On the best sites, old-growth Pseudotsuga menziesii grows to 46 m (150 ft) 

in height with diameters up to 236 cm (5 ft) at breast height. These trees may be 300 

years old. On north-facing slopes, associated tree species include Tsuga heterophylla

and Thuja plicata, both shade-tolerant, understory species. Acer macrophyllum is the 

most common broadleaf tree. Polystichum munitum is a very common component of 

the herbaceous community. There are large snags as well as wind-thrown trees scattered throughout. Areas that were clearcut in the past were planted with Pseudotsuga 

menziesii and now comprise a densely stocked new forest covering 43 ha (107 acres) 

with trees up to 20 cm (8 in) in diameter and 20-plus years old. 

See appendix tables 1, 2, and 3 for lists of vascular plants, lichens, and bryophytes—

liverworts and mosses—in the RNA.
10 

Horse Rock Ridge is a diverse area for wildlife owing to the various vegetative and 

cover types found there. The variety of habitats, elevations, soils, rock outcrops, seasonably available water, and wildlife foods and the inaccessibility by humans attract 

wildlife. A list of birds believed to frequent the RNA is given in appendix table 4; mammals are listed in appendix table 5; and mollusks, amphibians, and reptiles are listed in 

appendix table 6.

With settlement of the nearby Willamette Valley in the middle 1850s, people introduced farming and domestic animals to the area. The HRR area was likely grazed by 

sheep in the early 1900s. Their hooves helped to create bare ground that permitted 

erosion to occur on the steep slopes and provided a seedbed for introduced weeds. 

It is not known how severe the grazing was or how many years it may have lasted. It 

is known that no grazing has occurred since the early 1960s. Thirty-four introduced 

plants are now established at HRR (see app. table 1). Most of these species occur in 

small populations within the open areas or surrounding forest. One species, Senecio 

jacobaea, tansy ragwort, is considered a noxious plant. 

Land ownership in much of western Oregon is a checkerboard of private and public 

lands. In the early 1900s, timber companies began to harvest trees and built railroads, 

and later roads, to transport the logs to the mills. All of the original forest has been 

removed from private lands surrounding HRR, and the only old growth remains on a 

portion of the RNA. The surrounding area is now well roaded, and most of the land, 

regardless of ownership, is valuable commercial forest and is covered by healthy 

trees.

The Columbus Day (October 1962) windstorm caused extensive blowdown of timber 

throughout western Oregon. Exposed trees along the edges of open slopes at HRR 

were wind-thrown (see fig. 3). Later, a salvage timber sale was held to remove the 

downed timber where the topography permitted. On steeper slopes, trees were not 

salvaged, and remnants of many large trees felled by the wind can be seen protruding 

into the grasslands on the southern edge of the grassland/forest boundary. The BLM 

also has harvested timber as recently as 1980 in section 1 adjacent to the area that 

is now designated as the RNA. This clearcut area was broadcast burned and planted 

with Douglas-fir seedlings. 

With human population increasing in the southern Willamette Valley, all forest lands 

are being actively sought out for recreation purposes. To protect the open grassland at 

the RNA, rock berms have been constructed across several old logging roads within 

section 1, and a locked gate has been placed on the access road to a radio tower that 

is located at the very highest point within the RNA. This has reduced damage from 

vehicles and bikes on the open areas. Occasional hikers have worn a trail into the vegetation on the upper slopes. Since the 1970s, students have made botany field trips to 

the area. Hunters use the area in autumn.

There is no evidence of wildfire having burned through the RNA. There has been no 

mining activity on the area. 

In 2000, the BLM established transects in the RNA to characterize existing vegetation and to monitor long-term vegetation changes in the grassland, forest, and the 

ecotone between them. These permanent sample plots will be revisited in the future. 

Another study monitors forest vegetation to determine air quality by chemical analysis 

of lichens growing in the area. 

History of 

Disturbance

Research

Fauna
11

The RNA is suited to the study of succession of plant communities, wildlife use of 

midelevation dry grassland and adjacent forest, soil erosion, and forest growth. 

The topographic map applicable to the RNA is the 15 ′ Marcola, Oregon, quadrangle, 

scale 1:62,500, issued by the U.S. Geological Survey in 1950. The BLM, Eugene District Office, can supply information on the most recent aerial photographs and forest 

type maps for the area. Older aerial photos are available for reference at the University of Oregon library map room. For geologic information, consult the reconnaissance 

geologic map and sections of the western Cascade Range, Oregon, north of latitude 

43° N. (Peck et al. 1964).

1 millimeter (mm) = 0.04 inch (in)

1 centimeter (cm) = 0.4 inch (in)

1 meter (m) = 3.3 feet (ft)

1 kilometer (km) = 0.6 mile (mi) 

1 hectare (ha) = 2.47 acres

Degrees Celsius (°C) = (degrees Fahrenheit − 32)/1.8

Anderson, L.E.; Crum, H.A.; Buck, W.R. 1990. List of the mosses of North 

America north of Mexico. Bryologist. 93: 448–499.

Burt, W.H.; Grossenheider, R.P. 1980. A field guide to the mammals of North 

America north of Mexico. The Peterson Field Guide Series. 3rd ed. Boston and 

New York: Houghton Mifflin Company. 289 p. 

Esslinger, T.L.; Egan, R.S. 1995. A sixth checklist of the lichen-forming, 

Lichenicolous, and allied fungi of the Continental United States and Canada. 

Bryologist. 98: 467–549. 

Franklin, J.F.; Dyrness, C.T. 1973. Natural vegetation of Oregon and Washington. 

Gen. Tech. Rep. PNW-8. Portland, OR: U.S. Department of Agriculture, Forest 

Service, Pacific Northwest Forest and Range Experiment Station. 417 p. 

Hickman, J.C., ed. 1993. The Jepson manual, higher plants of California. Berkeley, 

CA: University of California Press. 1400 p. 

Hitchcock, C.L.; Cronquist, A. 1976. Flora of the Pacific Northwest. Seattle, WA: 

University of Washington Press. 730 p. 

Leonard, W.P.; Brown, H.A.; Jones, L.L.C. [et al.]. 1993. Amphibians of 

Washington and Oregon. Seattle, WA: Seattle Audubon Society. 168 p.

National Geographic Society. 1999. Field guide to the birds of North America. 

3rd ed. Washington, DC: National Geographic Society. 480 p. 

Oregon Natural Heritage Advisory Council. 1993. Oregon heritage plan.

Salem, OR: Oregon State Land Board.

Oregon State University. 2001. Oregon climate service. http://www.ocs.orst.edu. 

(August 2002).

Metric and English 

Equivalents

Literature Cited

Maps and Aerial 

Photographs
12 

Peck, D.L.; Gribbs, A.B.; Wells, F.G.; Dole, H.M. 1964. Geology of the central 

and northern parts of the western Cascade Range in Oregon. Prof. Pap. 449. 

Washington, DC: U.S. Geological Survey. 56 p.

Storm, R.M.; Leonard, W.P., eds. 1995. Reptiles of Washington and Oregon. 

Seattle, WA: Seattle Audubon Society. 176 p.

Stotler, R.; Crandall-Stotler, B. 1977. A checklist of the liverworts and hornworts 

of North America. Bryologist. 80: 405–428.

Turgeon, D.D., chair. 1998. Common and scientific names of aquatic invertebrates 

from the United States and Canada: mollusks. Special Publication 26. 2nd ed. 

Bethesda, MD: The American Fisheries Society. 526 p.

U.S. Department of Agriculture, Natural Resource Conservation Service 

[NRCS]. 1999. Soil taxonomy. Agric. Handb. 436. 2nd ed. Washington, DC: 

Government Printing Office. 869 p. 

U.S. Department of Agriculture, Soil Conservation Service [SCS]. 1987. Soil 

survey of Linn County, Oregon. 344 p. plus maps.

Vander Schaaf, D. 1993. Horse Rock Ridge Research Natural Area/area of critical 

environmental concern management plan. Eugene, OR: U.S. Department of the 

Interior, Bureau of Land Management. 51 p.
13

Table 1—Vascular plants found at Horse Rock Ridge Research Natural Areaa

Scientific nameb Common name

Acer circinatum Pursh Vine maple

Acer glabrum Torr. var. douglasii (Hook.) Dippel Douglas maple

Acer macrophyllum Pursh Bigleaf maple

Achillea millefolium L. Common yarrow

Achlys triphylla (Smith) DC. Vanillaleaf

Adenocaulon bicolor Hook. Pathfinder

Adiantum pedatum L. Maidenhair fern

Agrostis exarata Trin. var. monolepis (Torr.) Hitch. Spike bentgrass

Agrostis tenuis Sibth.c Colonial bentgrass

Aira caryophyllea L.c Silver hairgrass

Aira praecox L.c Early hairgrass

Allium acuminatum Hook. Tapertip onion

Allium amplectens Torr. Slimleaf onion

Allium crenulatum Wieg. Scalloped onion

Alnus rubra Bong. Red alder

Amelanchier alnifolia Nutt. Western serviceberry

Anemone deltoidea Hook. Threeleaf anemone

Apocynum androsaemifolium L. Spreading dogbane

Aquilegia formosa Fisch. Sitka columbine

Arabis glabra L. Bernh. Towermustard

Arbutus menziesii Pursh Pacific madrone

Arctostaphylos columbiana Piper Bristly manzanita

Arenaria macrophylla Hook. Bigleaf sandwort

Arenaria serphllifolia L. Thyme-leaf sandwort

Arenaria stricta Michx. Slender sandwort

Aspidotis densa (Brackenr.) Lellinger Aspidotis

Athyrium filix-femina (L.) Roth Lady-fern

Athysanus pusillus (Hook.) Greene Sandweed

Balsamorhiza deltoidea Nutt. Deltoid balsamroot

Barbarea orthoceras Ledeb. American wintercress

Berberis aquifolium Pursh Tall Oregongrape

Berberis nervosa Pursh Cascade Oregongrape

Blepharipappus scaber Hook. Blepharipappus

Brassica campestris L.c Field mustard

Brodiaea congesta Smith Field cluster lily or ookow

Brodiaea coronaria (Salisb.) Engl. Harvest brodiaea

Brodiaea hyacinthina (Lindl.) Baker Hyacinth brodiaea

Bromus mollis L.c Soft brome

Bromus orcuttianus Vasey Orcutt brome

Bromus pacificus Shear Pacific brome

Bromus rigidus Rothc Ripgut

Callitriche heterophylla var. bolanderi (Hegelm.) Fassett Water-starwort

Callitriche verna L. Spring water-starwort

Calocedrus (syn. Libocedrus) decurrens (Torr.) Florin Incense-cedar

Calochortus tolmiei H. & A. Cats-ear or Tolmie’s mariposa

Calypso bulbosa (L.) Oakes Calypso orchid

Appendix
14 

Table 1—Vascular plants found at Horse Rock Ridge Research Natural Area a (continued)

Scientific nameb Common name

Camassia leichtlinii (Baker) Wats. Leichtlin’s camas

Campanula scouleri Hook. Scouler’s bellflower

Cardamine oligosperma Nutt. Little western bittercress

Cardamine pulcherrima var. tenella (Pursh) Hitchc. Slender toothwort

Carex rossii Boott Ross sedge

Castanopsis chrysophylla (Dougl.) DC. Golden chinkapin or chinquapin

Castilleja hispida Benth. var. hispida Harsh paintbrush

Ceanothus sanguineus Pursh Redstem ceanothus

Ceanothus velutinus Dougl. Snowbrush

Centaurium muhlenbergii (Griseb.) Wight Muhlenberg’s centaury

Cerastium nutans Raf. Nodding chickweed

Cerastium viscosum L.c Sticky cerastium

Cheilanthes gracillima D.C. Eat. Lace lip-fern

Chimphila menziesii (R. Br.) Spreng. Little prince’s-pine

Chimphilla umbellata (L.) Bart. Prince’s-pine

Chrysanthemum leucanthemum L.c Oxeye-daisy

Circaea alpina L. Enchanter’s nightshade or Circaea

Cirsium vulgare (Savi) Tenore Bull thistle

Clarkia amoena (Lehm.) Nels. & Macbr. Farewell-to-spring

Clarkia gracilis (Piper) Nels. & Macbr. Slender godetia

Clarkia purpurea (Curtis) Nels. & Macbr. Purple godetia

Collinsia grandiflora Lindl. Large-flowered blue-eyed Mary

Collinsia parviflora Lindl. Small-flowered blue-eyed Mary

Collomia heterophylla Hook. Varied-leaf collomia

Corallorhiza maculata Raf. Spotted coral-root

Cornus nuttallii Aud. Pacific dogwood

Corylus cornuta Marsh. var. californica DC. Hazelnut or California hazel

Crataegus monogyna Jacq.c English hawthorn

Crepis sp. L. Hawksbeard

Cryptantha intermedia (Gray) Greene Common cryptantha

Cryptogramma acrostichoides (R. Br.) Clarke Rock-brake

Cynosurus echinatus L.c Hedgehog dogtail

Cystopteris fragilis (L.) Bernh. Brittle bladder-fern

Danthonia californica Boland. var. californica California danthonia

Daucus pusillus Michx. American carrot

Delphinium menziesii DC. Menzies’ larkspur

Dicentra formosa (Andr.) Walp. Pacific bleedingheart

Digitalis purpurea L.c Foxglove

Disporum smithii (Hook.) Piper Fairy lantern

Dodecatheon hendersonii Gray Broad-leaved shooting star

Dodecatheon pulchellum (Raf.) Merrill var. pulchellum Dark-throat shooting star

Draba verna L. Spring whitlow-grass 

Elymus glaucus Buckl. Blue wildrye

Epilobium minutum Lindl. Small-flowered willow-weed

Epilobium paniculatum Nutt. Autumn willow-weed

Erigeron compositus Pursh var. glabratus Macoun Cut-leaved daisy

Eriogonum nudum Dougl. Barestem buckwheat

Eriophyllum lanatum (Pursh) Forbes. Woolly sunflower
15

Table 1—Vascular plants found at Horse Rock Ridge Research Natural Area a (continued)

Scientific nameb Common name

Erodium circutarium (L.) L’Her.c Aifilaria or stork’s-bill

Erythronium oregonum Applegate Giant fawn-lily

Euphorbia peplus L. Petty spurge

Festuca idahoensis Elmer Idaho fescue

Festuca megalura Nutt.c Foxtail fescue

Festuca microstachys Nutt.c Small fescue

Festuca occidentalis Hook. Western fescue

Festuca subulata Trin. Bearded fescue

Fragaria vesca L. var. crinita (Rydb.) Hitchc. Strawberry

Fragaria virginiana Duchense var. platyphylla (Rydb.) Hall Broadpetal strawberry

Fritillaria lanceolata Pursh Rice-root fritillary

Galium aparine L. var. echinospermum (Wallr.) Farw. Bedstraw

Galium oreganum Britt. Oregon bedstraw

Galium triflorum Michx. Sweetscented bedstraw

Gaultheria shallon Pursh Salal

Geranium dissectum L.c Cut-leaf geranium

Geranium molle L.c Dovefoot geranium

Gilia capitata Sims Globe gilia

Githopsis specularioides Nutt. Githopsis or blue-cup

Gnaphalium palustre Nutt. Lowland cudweed

Goodyera oblongifolia Raf. Rattlesnake-plantain

Gratiola ebracteata Benth. Bractless hedge-hyssop

Habenaria elegans (Lindl.) Boland Elegant bog-orchid

Heterocodon rariflorum Nutt. Heterocodon

Heuchera micrantha Dougl. var. micrantha Small-flowered alumroot

Hieracium albiflorum Hook. White-flowered hawkweed

Holcus lanatus L.c Common velvet-grass

Holodiscus discolor (Pursh) Maxim. Ocean-spray

Hordeum geniculatum All.c Barley

Hypericum perforatum L. Common St. John’s wort

Hypochaeris glabra L. Smooth cats-ear

Hypochaeris radicata L.c False dandelion or spotted cats-ear

Iris chrysophylla Howell Slender-tubed iris

Iris tenax Dougl. Oregon iris

Isoetes nuttallii A. Br. Nuttall’s quillwort

Juncus bufonius L. Toad rush

Juncus kelloggii Engelm. Kellogg’s rush

Kelloggia galioides Torr. Kelloggia

Koeleria cristata Pers. Prairie Junegrass

Lactuca muralis (L.) Fresen. Wall lettuce

Lathyrus polyphyllus Nutt. Leafy peavine

Leontodon nudicaulis (L.) Meratc Hairy hawkbit

Linanthus bicolor (Nutt.) Greene var. bicolor Bicolored linanthus 

Linnaea borealis L. var. longiflora Torr. Twinflower

Linum usitatissimum L.c Common flax

Lithophragma parviflora (Hook.) Nutt. Smallflowered woodlandstar

Lomatium utriculatum (Nutt.) Coult. & Rose Common lomatium

Lonicera ciliosa (Pursh) DC. Orange honeysuckle
16 

Table 1—Vascular plants found at Horse Rock Ridge Research Natural Area a (continued)

Scientific nameb Common name

Lonicera hispidula (Lindl.) Dougl. Hairy honeysuckle

Lotus micranthus Benth. Small-flowered deervetch or lotus

Lupinus lepidus Dougl. Prairie lupine

Lupinus micranthus Dougl. Small-flowered field lupine

Luzula campestris (L.) DC. var. congesta (Thuill.) E. Meyer Field woodrush

Madia exigua (J.E. Smith) Gray Little tarweed

Madia gracilis (J.E. Smith) Keck Slender tarweed

Madia madioides (Nutt.) Greene Woodland tarweed

Madia minima (Gray) Keck Small-head tarweed

Marah oreganus (T. & G.) Howell Oregon bigroot

Melica subulata (Griseb.) Scribn. Alaska oniongrass

Microsteris gracilis (Hook.) Greene var. gracilis Pink microsteris

Mimulus alsinoides Dougl. Chickweed

Mimulus guttatus DC. Yellow monkey-flower

Montia parvifolia (Moc.) Greene Littleleaf montia

Montia perfoliata (Donn) Howell Miner’s lettuce

Montia sibirica (L.) Howell Western springbeauty

Montia spanthulata (Dougl.) Howell Pale montia

Myosotis discolor Pers.c Yellow and blue forget-me-not

Nemophila parviflora Dougl. Small-flowered nemophila

Nothochelone nemorosa (Dougl.) Straw. Woodland beard-tongue

Orobanche fasciculata Nutt. Clustered broomrape

Orobanche uniflora L. var. minuta (Suksd.) Beck Naked broomrape

Orobanche uniflora L. var. purpurea (Heller) Achey Naked broomrape

Orothocarpus attenuatus Gray Narrow-leaved owl-clover

Orthocarpus hispidus Benth. Hairy owl-clover

Orthocarpus pusillus Benth. Dwarf owl-clover

Osmorhiza chilensis H. & A. Mountain sweet-root

Oxalis oregana Nutt. Oregon oxalis

Pachistima myrsinites (Pursh) Raf. Oregon boxwood

Penstemon sp. Mitch. Penstemon

Perideridia gairdneri (H. & A.) Math. Gairdner’s yampah

Phacelia linearis (Pursh) Holz. Threadleaf phacelia

Phacelia nemoralis Greene Woodland phacelia

Phacelia sericea (Grah.) Gray var. ciliosa Rydb. Silky phacelia

Philadelphus lewisii Pursh Lewis mockorange

Phlox adsurgens Torr. Woodland phlox 

Physocarpus capitatus (Pursh) Kuntze Pacific ninebark

Pityrogramma triangularis (Kaulf.) Maxon. Gold-fern

Plagiobothrys scouleri (H. & A.) Johnst. Scouler’s popcorn-flower

Plantago lanceolata L.c English plantain

Plectritis congesta (Lindl.) DC. Rosy plectritis

Plagiobothrys scouleri (H. & A.) Johnst. var. scouleri Scouler’s popcorn-flower

Poa pratensis L.c Kentucky bluegrass

Poa scabrella (Thurb.) Benth. Pine bluegrass

Poa secunda Pine bluegrass

Polypodium glycyrrhiza D.C. Eat. Licorice-fern

Polystichum munitum (Kaulf.) Presl Sword-fern
17

Table 1—Vascular plants found at Horse Rock Ridge Research Natural Area a (continued)

Scientific nameb Common name

Potentilla glandulosa Lindl. var. glandulosa Sticky cinquefoil

Prunella vulgaris L.c Self-heal

Prunus emarginata (Dougl.) Walp. Bitter cherry

Pseudotsuga menziesii (Mirb.) Franco Douglas-fir

Psoralea physodes Dougl. California-tea

Pteridium aquilinum (L.) Kuhn Bracken fern

Quercus garryana Dougl. Oregon white oak

Ranunculus occidentalis Nutt. var. occidentalis Western buttercup

Rhamnus purshiana DC. Cascara

Rhus diversiloba T. & G. Poison-oak

Ribes sanguineum Pursh Red-flowered currant

Rosa gymnocarpa Nutt. Baldhip rose

Rubus leucodermis Dougl. Blackcap

Rubus parviflorus Nutt. Thimbleberry

Rubus ursinus Cham. & Schlecht var. macropetalus (Dougl.) Brown Pacific blackberry

Rumex acetosella L.c Sheep sorrel

Rumex crispus L.c Curly dock

Salix geyeriana Anderss. Geyer willow

Salix scouleriana Barratt Scouler willow

Salix sitchensis Sanson Sitka willow

Sanicula bipinnatifida Dougl. Purple sanicle 

Sanicula crassicaulis Poepp. Pacific sanicle

Satureja douglasii (Benth.) Briq. Yerba buena

Saxifraga caespitosa L. var. subgemmifera (Engl. & Irmsch.) Hitchc. Tufted saxifrage

Saxifraga integrifolia Hook. var. integrifolia Swamp saxifrage

Saxifraga nuttallii Small Nuttall’s saxifrage

Saxifraga occidentalis Wats. var. rufidula (Small) Hitchc. Western saxifrage

Sedum lanceolatum Torr. var. lanceolatum Lanceleaved sedum

Sedum oregonense (Wats.) Peck Creamy stonecrop

Sedum roseum (L.) Scop. King’s crown

Sedum spathulifolium Hook. Spatula-leaf sedum

Selaginella wallacei Hieron Wallace’s selaginella

Senecio intergerrimus Nutt. var. exaltatus (Nutt.) Cronq. Western groundsel 

Senecio jacobaea L.c Tansy ragwort 

Sherardia arvensis L.c Blue field-madder

Sidalcea virgata Howell Sidalcea

Silene gallica L. Windmill pink

Smilacina stellata (L.) Desf. Star-flowered Solomon-plume

Sonchus asper (L.) Hill c Prickly sow-thistle

Spiranthes romanzoffiana Cham. Hooded ladies-tresses

Stachys cooleyae Heller Cooley’s hedge-nettle

Stellaria nitens Nutt. Shining chickweed

Stipa lemmonii (Vasey) Scribn. Lemmon’s needlegrass

Symphoricarpos albus (L.) Blake Common snowberry

Symphoricarpos mollis Nutt. Creeping snowberry

Synthyris reniformis (Dougl.) Benth. Snow-queen

Taraxacum officinnale Weber c Dandelion

Taxus brevifolia Nutt. Pacific yew
18 

Table 1—Vascular plants found at Horse Rock Ridge Research Natural Area a (continued)

Scientific nameb Common name

Thalictrum occidentale Gray Western meadowrue

Thuja plicata Donn Western redcedar

Thysanocarpus curvipes Hook. Sand fringepod

Trichostema lanceolatum Benth. Blue-curls or vinegar weed

Trientalis latifolia Hook. Western starflower

Trifolium microcephalum Pursh Woolly clover

Trifolium microdon H. & A. Thimble clover

Trifolium repens L.c White clover

Trifolium subterraneum L.c Subterranean clover

rifolium tridentatum Lindl. Sand clover

Trifolium variegatum Nutt. White-tip clover

Trifolium wormskjoldii Lehm. Springbank clover

Trillium ovatum Pursh Trillium

Trisetum canescens Buckl. Tall trisetum

Tsuga heterophylla (Raf.) Sarg. Western hemlock

Vaccinium parvifolium Smith Red huckleberry

Valeriana sitchensis Bong. Sitka valerian

Veronica arvensis L.c Common speedwell

Viburnum ellipticum Hook. Oregon viburnum

Vicia americana Muhl. American vetch

Vicia gigantea Hook. Giant vetch

Viola sempervirens Greene Evergreen violet

Whipplea modesta Torr. Whipplevine or modesty

Zigadenus venenosus Wats. var. venenosus Death-camas

a Information supplied by Cheshire Mayrsohn, botanist, and Nancy Wogen, plant ecologist, Bureau of Land 

Management, Eugene, OR; Alan B. Curtis, retired BLM forester/botanist, Eugene, OR; John Christy, former BLM 

botanist, Oregon Natural Heritage Program, Portland, OR; Peter Zika, former BLM botanist and consultant, Seattle, 

WA; Reid Schuller, ecologist, Natural Areas Association, Bend, OR; Bruce Newhouse, botanist, Salix Associates, 

Eugene, OR.

b Nomenclature follows Hitchcock and Cronquist (1976). For name changes, refer to Hickman (1993).

c Introduced species.
19

Table 2—Lichens found at Horse Rock Ridge Research Natural Area a

Scientific nameb

Adelolecia pilati (Hepp) Hertl & Hafellner

Alectoria imshaugii Brodo & D. Hawksw.

Alectoria sarmentosa (Ach.) Ach.

Alectoria vancouverensis (Gyelnik) Gyelnik ex Brodo & D. Hawksw.

Arthonia radiata (Pers.) Ach.

Arthopyrenia antecellens (Nyl.) R.C. Harris

Aspicilia caesiocinerea (Nyl. ex Malbr.) Arnold

Aspicilia mastrucata (Wahlenb.) Th. Fr. 

Baeomyces rufus (Hudson) Rebent.

Bryoria friabilis Brodo & D. Hawksw.

Bryoria fuscescens (Gyelnik) Brodo & D. Hawksw.

Bryoria ` sp. sensu McCune & Geiser (1997)

Bryoria pseudofuscescens (Gyelnik) Brodo & D. Hawksw.

Bryoria trichodes (Michaux) Brodo & D. Hawksw.

Buellia punctata (Hoffm.) A. Massal.

Buellia sp. De Not.

Caloplaca ferruginea (Hudson) Th. Fr.

Caloplaca lithophila H. Magn.

Caloplaca trioliensis Zahlbr.

Candelaria concolor (Dickson) Stein

Candelariella dispersa (Rasanen) Hakul.

Candelariella terrigena Rasanen

Candelariella vitellina (Hoffm.) Mull. Arg.

Candelariella xanthostigma (Ach.) Lettau

Catillaria chalybeia (Borrer) A. Massal.

Cavernularia hultenii Degel.

Cetraria chlorophylla (Willd.) Hale

Cetraria orbata (Nyl.) M.J. Lai

Cladonia borealis S. Stenroos

Cladonia cariosa (Ach.) Sprengel

Cladonia chlorophaea (Florke ex Sommerf.) Sprengel

Cladonia fimbriata (L.) Fr.

Cladonia furcata (Hudson) Schrader

Cladonia ochrochlora Florke

Cladonia pocillum (Ach.) Grognot

Cladonia pxyidata (L.) Hoffm.

Cladonia squamosa var. subsquamosa (Nyl. ex Leighton) Vainio

Cladonia transcendens (Vainio) Vainio

Cladonia verruculosa (Vainio) Ahti

Coelocaulon aculeatum (Schreber) Link

Collema glebulentum (Nyl. ex Crombie) Degel.

Dermatocarpon intestiniforme (Korber) Hasse

Dermatocarpon miniatum (L.) W. Mann

Diploschistes muscorum (Scop.) R. Sant.

Diploschistes scruposus (Schreber) Norman

Ephebe lanata (L.) Vainio

Ephebe solida Bornet

Euopsis granatina (Sommerf.) Nyl.
2

0

Table 2—Lichens found at Horse Rock Ridge Research Natural Area a 

(continued)

Scientific nameb 

Evernia prunastri (L.) Ach.

Fuscopannaria aurita P.M. Jorg.

Fuscopannaria pulveracea (P.M. Jorg. & Henssen) P.M. Jorg.

Fuscopannaria thiersii P.M. Jorg.

Hypocenomyce castaneocinerea (Rasanen) Timdal

Hypocenomyce scalaris (Ach.) Choisy

Hypogymnia enteromorpha (Ach.) Nyl.

Hypogymnia imshaugii Krog

Hypogymnia inactiva (Krog) Ohlsson

Hypogymnia metaphysodes (Asah.) Rass.

Hypogymnia occidentalis L. Pike

Hypogymnia physodes (L.) Nyl.

Hypogymnia tubulosa (Schaerer) Hav.

Hypotrachyna sinuosa (Sm.) Hale

Japewia tornoensis (Nyl.) Tonsberg

Lecanora carpinea (L.) Vainio

Lecanora hagenii (Ach.) Ach.

Lecanora pacifica Tuck.

Lecanora pulicaris (Pers.) Ach.

Lecanora rupicola (L.) Zahlbr.

Lecanora semitensis Tuck.

Lecanora zosterae (Ach.) Nyl.

Lecidea atrobrunnea (Raymond ex Lam. & DC.) Schaerer

Lecidea dolodes Nyl.

Lecidea enalla Fr. 

Lecidea mannii Tuck.

Lecidea tessellata Florke

Lecidea sp. Ach.

Lecidella elaeochroma (Ach.) Hazsl.

Lecidella stigmatea (Ach.) Hertel & Leuckert

Lecidella wulfenii (Hepp) Korber

Leprocaulon subalbicans (Lamb) Lamb & Ward

Leproloma cacuminum (A. Massal.) Lothander

Leproloma vouauxii (Hue) J.R. Laundon

Leptochidium albociliatum (Desmaz.) Choisy

Leptogium corniculatum (Hoffm.) Minks

Leptogium lichenoides (L.) Zahlbr.

Leptogium saturninum (Dickson) Nyl.

Leptogium tacomae P.M. Jorg.

Letharia vulpina (L.) Hue

Lichenella stipatula Nyl.

Lobaria oregana (Tuck.) Mull. Arg.

Lobaria pulmonaria (L.) Hoffm.

Lobaria scrobiculata (Scop.) DC.

Lobothallia alphoplaca (Wahlenb.) Hafellner

Loxosporopsis corallifera Brodo, Henssen & Imahsug

Melanelia exasperatula (Zahlbr.) Essl.
21

Table 2—Lichens found at Horse Rock Ridge Research Natural Area a 

(continued)

Scientific nameb 

Melanelia fuliginosa (Fr. ex Duby) Essl. 

Melanelia panniformis (Nyl.) Essl.

Melanelia subelegantula (Essl.) Essl.

Menegazzia terebrata (Hoffm.) A. Massal.

Mycoblastus sanguinarius (L.) Norman

Neofuscelia verruculifera (Nyl.) Essl.

Nephroma laevigatum Ach.

Nodobryoria oregana (Tuck.) Common & Brodo

Normandina pulchella (Borrer) Nyl.

Ochrolechia oregonensis H. Magn.

Ochrolechia subpallescens Vers.

Ochrolechia upsaliensis (L.) A. Massal

Ophioparma rubicosa (Muell. Arg.) Ekman

Parmelia hygrophila Goward & Ahti

Parmelia pseudosulcata Gyelnik

Parmelia saxatilis (L.) Ach.

Parmelia sulcata Taylor

Parmeliopsis hyperopta (Ach.) Arnold

Peltigera britannica (Gyelnik) Holt.-Hartw. & Tonsb.

Peltigera collina (Ach.) Schrader

Peltigera leucophlebia (Nyl.) Gyelnik

Peltigera membranacea (Ach.) Nyl.

Peltigera praetextata (Florke ex Sommerf.) Zopf

Pertusaria amara (Ach.) Nyl.

Pertusaria borealis Erichsen

Pertusaria leucostoma A. Massal.

Pertusaria ophthalmiza (Nyl.) Nyl.

Pertusaria stenhammari Hellb.

Pertusaria subambigens Dibben

Pertusaria sp. DC.

Phlyctis argena (Sprengel) Flotow

Phlyctis speirea G. Merr.

Phylliscum demangeonii (Moug. & Mont.) Nyl.

Physcia adscendens (Fr.) H. Olivier

Physcia aipolia (Ehrh. ex Humb.) Furnr.

Physcia tenella (Scop.) DC.

Physconia enteroxantha (Nyl.) Poelt

Physconia perisidiosa (Erichsen) Moberg

Pilophorus acicularis (Ach.) Th. Fr.

Placopsis gelida (L.) Lindsay

Placynthiella uliginosa (Schrader) Coppins & P. James

Platismatia glauca (L.) Culb. & C. Culb.

Platismatia herrei (Imshaug) Culb. & C. Culb.

Platismatia stenophylla (Tuck.) Culb. & C. Culb.

Polyblastia sp. A. Massal.

Polychidium muscicola (SW.) Gray

Polysporina simplex (Davies) Vezda
2

2

Table 2—Lichens found at Horse Rock Ridge Research Natural Area a 

(continued)

Scientific nameb 

Porpidia crustulata (Ach.) Hertel & Knoph

Protoparmelia badia (Hoffm.) Hafellner

Protoparmelia ochrococca P.M. Jorg., Rambold & Hertel

Pseudocyphellaria anomala Brodo & Ahti

Pseudocyphellaria anthraspis (Ach.) H. Magn.

Pseudocyphellaria crocata (L.) Vainio

Psora nipponica (Zahlbr.) Gotth. Schneider 

Ramalina dilacerata (Hoffm.) Hoffm.

Ramalina farinacea (L.) Ach.

Rhizocarpon copelandii (Korber) Th. Fr.

Rhizocarpon geminatum Korber

Rhizocarpon sp. Ramond ex DC.

Rimularia insularis (Nyl.) Rambold & Hertel

Rinodina archaea (Ach.) Arnold

Rinodina hallii Tuck.

Rinodina stictica Sheard & Tonsberg

Rinodina sp. (Ach.) Gray

Schaereria cinereorufa (Schaerer) Th. Fr.

Schaereria fuscocinerea (Nyl.) Clauzade & Roux

Sphaerophorus globosus (Hudson) Vainio

Stenocybe clavata Tibell

Stereocaulon intermedium (Savicz) H. Magn.

Stereocaulon sterile (Savicz) Lamb ex Krog

Stereocaulon tomentosum Fr.

Sticta fuliginosa (Hoffm.) Ach. 

Sticta limbata (Sm.) Ach.

Tephromela atra (Hudson) Hafellner

Thamnolia vermicularis (Sw.) Ach. ex Schaerer

Trapeliopsis flexuosa (Fr.) Coppins & P. James

Trapeliopsis wallrothii (Florke) Hertel & Gotth. Schneider

Umbilicaria phaea Tuck.

Umbilicaria torrefacta (Lightf.) Schrader

Usnea cavernosa Tuck.

Usnea diplotypus Vainio

Usnea filipendula Stirton

Usnea pacificana Halonen 

Usnea scabrata Nyl. 

Usnea subfloridana Stirton

Usnea wirthii P. Clerc

Xanthoparmelia angustiphylla (Gyelnik) Hale

Xanthoparmelia cumberlandia (Gyelnik) Hale

Xanthoria polycarpa (Hoffm.) Rieber

Xylographa parallela (Ach.:Fr.) Behlen & Desberg

a Information supplied by Bruce McCune, Professor, Oregon State University, Corvallis, 

OR; Sherwood, M. 1979. (4 April) Letter on file with: district botanist, USDI Bureau of Land 

Management, P.O. Box 10226, Eugene, OR 97440-2226.

b Nomenclature follows Esslinger and Egan (1995).
23

Table 3—Bryophytes found at Horse Rock Ridge Research Natural Area a

Scientific nameb

Liverworts:

Asterella californica (Hampe) Underw.

Cephaloziella divaricata (Sm.) Schiffn.

Douinia ovata (Dicks.) H. Buch

Frullania californica (Austin) A. Evans

Gymnomitrion obtusum (Lindb.) Pears.

Marsupella emarginata (Ehrh.) Dumort.

Plagiochila porelloides (Torr. ex Nees) Lindenb.

Scapania americana Muell. Frib.

Scapania paludosa (Muell. Frib.) Muell. Frib.

Mosses:

Amphidium californicum (Hampe ex C. Muell.) Broth.

Anacolia menziesii (Turn.) Par.

Antitrichia curtipendula (Hedw.) Brid.

Atrichum selwynii Aust.

Bartramia pomiformis Hedw.

Blindia acuta (Hedw.) Bruch & Schimp in B.S.G. 

Bryum argenteum Hedw.

Bryum miniatum Lesq.

Ceratodon purpureus (Hedw.) Brid.

Claopodium bolanderi Best.

Dicranum scoparium Hedw.

Didymodon vinealis (Brid.) Zand.

Encalypta ciliata Hedw.

Entosthodon fascicularis (Hedw.) C. Muell.

Eurhynchium oreganum (Sull.) Jaeg.

Funaria hygrometrica Hedw.

Grimmia pulvinata (Hedw.) Sm.

Grimmia torquata Hornsch. in Grev.

Homalothecium fulgescens (Mitt. ex C. Muell.) Lawt.

Hylocomium splendens (Hedw.) Schimp. in B.S.G. 

Hypnum subimponens Lesq.

Isothecium myosuroides Brid.

Orthotrichum lyellii Hook. & Tayl.

Orthotrichum pulchellum Brunt. in Winch. & Gateh.

Orthotrichum rupestre Schleich. ex Schwaegr.

Orthotrichum speciosum Nees in Sturm

Philonotis fontana (Hedw.) Brid.

Plagiomnium venustum (Mitt.) T. Kop.

Pleuridium subulatum (Hedw.) Rabenh.

Pohlia cruda (Hedw.) Lindb.

Polytrichastrum alpinum (Hedw.) G.L. Sm.

Polytrichum juniperinum Hedw.

Polytrichum piliferum Hedw.

Pseudobraunia californica (Lesq.) Broth.

Racomitrium aciculare (Hedw.) Brid.

Racomitrium canescens (Hedw.) Brid.
24 

Table 3—Bryophytes found at Horse Rock Ridge Research Natural Area a 

(continued)

Scientific nameb

Racomitrium elongatum Ehrh. ex Frisv.

Racomitrium heterostichum (Hedw.) Brid.

Rhytidiadelphus triquetrus (Hedw.) Warnst.

Scleropodium cespitans (C. Muell.) L. Koch

Timmiella crassinervis (Hampe) L. Koch

Tortula ruralis (Hedw.) Gaertn. et al.

Trachybryum megaptilum (Sull.) Schof.

Weissia controversa Hedw.

a Information supplied by John Christy, former BLM botanist, Oregon Natural Heritage Program, 

Portland, OR, and Bruce Newhouse, botanist, Salix Associates, Eugene, OR.

b Nomenclature follows Anderson et al. (1990) and Stotler and Crandall-Stotler (1977).
25

Table 4—Birds expected to use Horse Rock Ridge Research Natural Area a

Family Scientific nameb Common name

Ardeidae Ardea herodias Great blue heron

Butorides virescens Green heron

Cathartidae Cathartes aura Turkey vulture

Accipitridae Accipiter cooperii Cooper’s hawk

Accipiter gentilis Northern goshawk

Accipiter striatus Sharp-shinned hawk

Aquila chrysaetos Golden eagle

Buteo jamaicensis Red-tailed hawk

Falconidae Falco sparverius American kestrel

Phasianidae Bonasa umbellus Ruffed grouse

Dendragapus obscurus Blue grouse

Odontophoridae Oreortyx pictus Mountain quail

Columbidae Columba fasciata Band-tailed pigeon

Zenaida macroura Mourning dove

Tytonidae Tyto alba Barn owl

Strigidae Aegolius acadicus Northern saw-whet owl

Bubo virginianus Great horned owl

Glaucidium gnoma Northern pygmy owl

Otus kennicottii Western screech owl

Strix nebulosa Great gray owl

Strix occidentalis Spotted owl

Strix varia Barred owl

Caprimulgidae Chordeiles minor Common nighthawk

Apodidae Chaetura vauxi Vaux’s swift

Trochilidae Selasphorus rufus Rufous hummingbird

Stellula calliope Calliope hummingbird

Picidae Colaptes auratus Northern flicker

Dryocopus pileatus Pileated woodpecker

Picoides pubescens Downy woodpecker

Picoides villosus Hairy woodpecker

Sphyrapicus ruber Red-breasted sapsucker

Tyrannidae Contopus cooperi Olive-sided flycatcher

Contopus sordidulus Western wood-pewee

Empidonax difficilis Pacific-slope flycatcher

Empidonax hammondii Hammond’s flycatcher

Empidonax oberholseri Dusky flycatcher

Vireonidae Vireo cassinii Cassin’s vireo

Vireo gilvus Warbling vireo

Vireo huttoni Hutton’s vireo

Vireo solitarius Blue-headed vireo
26 

Table 4—Birds expected to use Horse Rock Ridge Research Natural Area a 

(continued)

Family Scientific nameb Common name

Corvidae Corvus brachyrhynchos American crow

Corvus corax Common raven

Cyanocitta stelleri Steller’s jay

Perisoreus canadensis Gray jay

Hirundinidae Progne subis Purple martin

Tachycineta thalassina Violet-green swallow

Paridae Poecile atricapillus Black-capped chickadee

Poecile rufescens Chestnut-backed chickadee

Aegithalidae Psaltriparus minimus Bushtit

Certhiidae Certhia americana Brown creeper

Sittidae Sitta canadensis Red-breasted nuthatch

Troglodytidae Troglodytes troglodytes Winter wren

Regulidae Regulus calendula Ruby-crowned kinglet

Regulus satrapa Golden-crowned kinglet

Turdidae Catharus guttatus Hermit thrush

Catharus ustulatus Swainson’s thrush 

Ixoreus naevius Varied thrush

Turdus migratorius Robin

Parulidae Dendroica coronata Yellow-rumped warbler

Dendroica nigrescens Black-throated gray warbler

Dendroica occidentalis Hermit warbler

Dendroica townsendi Townsend’s warbler

Oporornis tolmiei MacGillivray’s warbler

Vermivora celata Orange-crowned warbler

Wilsonia pusilla Wilson’s warbler

Thraupidae Piranga ludoviciana Western tanager

Emberizidae Junco hyemalis Dark-eyed junco

Melospiza melodia Song sparrow

Pipilo erythrophthalmus Rufous-sided towhee

Cardinalidae Pheucticus melanocephalus Black-headed grosbeak

Fringillidae Carduelis pinus Pine siskin

Carduelis tristis American goldfinch

Carpodacus purpureus Purple finch

Coccothraustes vespertinus Evening grosbeak

Loxia curvirostra Red crossbill

a Information supplied by Paula Larson, wildlife biologist, Bureau of Land Management, Eugene, OR, and 

Charles Thomas, former BLM wildlife biologist.

b Birds listed are expected to use the area at some time of year.

c Nomenclature follows National Geographic Society (1999).
27

Table 5—Mammals expected to use Horse Rock Ridge Research Natural Area a 

Family Scientific nameb Common name

Didelphiidae Didelphis marsupialis Opossum

Soricidae Sorex trowbridgei Trowbridge shrew

Sorex vagrans Vagrant shrew

Talpidae Neurotrichus gibbsi Shrew-mole

Scapanus orarius Pacific mole

Vespertilionidae Antrozous pallidus Pallid bat

Eptesicus fuscus Big brown bat

Lasionycteris noctivagans Silver-haired bat

Lasiurus cinereus Hoary bat

Myotis californicus California myotis

Myotis evotis Long-eared myotis 

Myotis lucifugus Little brown myotis 

Myotis thysanodes Fringed myotis 

Myotis volans Long-legged myotis

Myotis yumanensis Yuma myotis 

Plecotus townsendi Western big-eared bat

Ursidae Ursus americanus Black bear

Procyonidae Procyon lotor Raccoon

Mustelidae Mephitis mephitis Striped skunk

Mustela erminea Short-tailed weasel

Mustela frenata Long-tailed weasel

Spilogale putorius Spotted skunk

Canidae Canis latrans Coyote

Urocyon cineroargenteus Gray fox

Vulpes fulva Red fox

Felidae Felis concolor Mountain lion

Lynx rufus Bobcat

Aplodontiidae Aplodontia rufa Mountain beaver

Sciuridae Eutamias townsendi Townsend chipmunk

Glaucomys sabrinus Northern flying squirrel

Sciurus griseus Western gray squirrel

Tamiasciurus douglasi Chickaree

Cricetidae Clethrionomys occidentalis Western redback vole

Microtus oregoni Creeping or Oregon vole

Microtus townsendi Townsend vole

Neotoma fuscipes Dusky-footed woodrat

Peromyscus maniculatus Deer mouse

Phenacomys longicaudus Red tree vole

Zapodidae Zapus trinotatus Pacific jumping mouse
28 

Table 5—Mammals expected to use Horse Rock Ridge Research Natural Area a 

(continued)

Family Scientific nameb Common name

Leporidae Lepus americanus Snowshoe hare

Sylvilagus bachmani Brush rabbit

Erethrizontidae Erethizon dorsatum Porcupine

Cervidae Cervus elaphus Elk 

Odocoileus hemionus Blacktail deer 

a Information supplied by Paula Larson, BLM wildlife biologist, Eugene, OR; and Charles Thomas, 

former BLM wildlife biologist.

b Mammals listed are expected to use the area at some time of year.

c Nomenclature follows Burt and Grossenheider (1980).
29

Table 6—Mollusks, amphibians, and reptiles expected to use Horse 

Rock Ridge Research Natural Areaa b

Scientific namec Common name

Mollusks:

Probably present—

 Ancotrema sportella Beaded lancetooth (snail)

 Ariolimax columbianus Pacific bananaslug

 Haplotrema vancouverense Robust lancetooth (snail)

 Monadenia fidelis Pacific sideband (snail)

Possibly present—

 Ancotrema hybridum Oregon lancetooth (snail)

 Carychium occidentale Western thorn (small snail d)

 Cryptomastix germana Pygmy Oregonian (small snail d)

 Deroceras laeve Meadow slug

 Euconulus fulvus alaskensis Western brown hive (small snail d)

 Megomphix hemphilli Oregon megomphix e (snail)

 Nearctula rowelli Threaded vertigo (small snail d)

 Pristiloma arcticum crateris Crater Lake tightcoile (small snail d)

 Pristiloma lansingi Denticulate tightcoil (small snail d)

 Pristiloma stearnsii Striate tightcoil (small snail d)

 Prophysaon andersoni Reticulate taildropper (slug)

 Prophysaon coeruleum Blue-gray taildropper (slug)

 Prophysaon dubium Papillose taildropper (slug)

 Punctum randolphii Conical spot (small snail d)

 Striatura pugetensis Northwest striate (small snail d)

 Vespericola columbianus Northwest hesperian (snail)

Amphibians:

Probably present—

 Ambystoma gracile Northwestern salamander

 Dicamptodon tenebrosus Pacific giant salamander

 Ensatina eschscholtzii Ensatina (salamander)

 Hyla regilla Pacific treefrog

 Plethodon dunni Dunn’s salamander

 Taricha granulosa Rough-skinned newt

Possibly present—

 Aneides ferreus Clouded salamander e

 Batrachoseps wrightorum Oregon slender salamander e

 Rana aurora aurora Northern red-legged froge

Reptiles:

Probably present—

 Charina bottae Rubber boa

 Diadophis punctatus Ringneck snake

 Elgaria coerulea Northern alligator lizard

 Eumeces skiltonianus Western skink

 Thamnophis ordinoides Northwestern garter snake

 Thamnophis sirtalis Common garter snake
30

Table 6—Mollusks, amphibians, and reptiles expected to use Horse 

Rock Ridge Research Natural Areaa b (continued)

Scientific namec Common name

Possibly present—

 Coluber constrictor Racer (snake)

 Contia tenuis Sharptail snakee

 Elgaria multicarinata Southern alligator lizard

 Pituophis catenifer Gopher snake

 Sceloporus occidentalis Western fence lizard

 Thamnophis elegans Western terrestrial garter snake

a Information supplied by John Applegarth, wildlife biologist, Bureau of Land Management, 

Eugene, OR 97440.

b Species listed are expected to use the area at some time of year.

c Nomenclature follows Turgeon (1998) for mollusks, Leonard et al. (1993) for amphibians, 

and Storm and Leonard (1995) for reptiles.

d For this list a “small snail” is defined as having a shell that is less than 1 centimeter in 

diameter or length when mature.

e Species listed as “special status” with the Oregon Natural Heritage Program as of 

February 2001.
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