CPC National Collection Plant Profile
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Eriogonum crosbyae
Family: |
Polygonaceae |
Common Name: |
Crosby's buckwheat |
Author: |
Reveal |
Growth Habit: |
Perennial |
CPC
Number: |
1708 |
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Primary
custodian for this plant in the CPC National Collection of Endangered
Plants is: |
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Edward Guerrant, Ph.D. contributed to this Plant Profile. |
Eriogonum crosbyae
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With just over 160,000 individuals in Nevada and over 16,000 in Oregon (Kaye et al. 1990 and NNHP 2001b), it is natural to wonder why scientists and land managers are concerned about this species. Despite this large number of plants, over 85% of the populations in Nevada lie within a mining company's lease area. Eriogonum crosbyae seems to have extremely specific soil requirements. It grows only in light-tan to white volcanic tuff (ash) deposits that were laid down 8-12 million years ago in shallow lakes. This soil type is scattered throughout northwest Nevada and southeast Oregon. Mining will likely destroy this habitat type and this species' chance for continued survival.
Distribution
& Occurrence |
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State Range
Habitat
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Eriogonum crosbyae grows only on gentle to steep slopes comprised of light-tan to white volcanic ash deposits. Precipitation averages 8 to 10 inches per year. Associated species are sparse but include: Astragalus spp., Atriplex confertifolia, Chrysothamnus nauseosus, Tetradymia glabrata, Artemisia spp., Elymus cinereus, Stanleya viridiflora, Sphaeralcea, Ipomopsis congesta,and frequently Astragalus tiehmii. |
Distribution
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OR, NV
OR: Basin and Range (Lake and Harney Counties)
NV: Most clustered in Washoe County, 1 isolated population in Humboldt Co.
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Number Left
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9 sites in Oregon. Two sites have two populations each, for a total of 11 populations. Population sizes range from 12 to 6,900-but many have not been surveyed since 1980. Most occurrences are on State land, a few on BLM (ONHPDB 2000). In Nevada, there are about 30 occurrences with a total of 160,000 individuals estimated. Most Nevada occurrences are on BLM land, a few on private (NNHP 2001b). |
State/Area
Protection
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State/Area |
Rank |
Status |
Date |
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Conservation,
Ecology & Research |
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Ecological
Relationships
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Eriogonum crosbyae is a strange looking plant. It grows 10cm-25cm across, low to the ground and may be either dense or loosely matted. The leaves are densely hairy, and the flowering stems are covered with soft woolly hairs. The flowers are a bright yellow and many are held together in round flowering heads. Eriogonum crosbyae flowers from late May to early August (NNHP 2001b).
The plants found growing in Nevada appear more robust than those in Oregon. The clumps are larger and cover a greater area. The soil substrates in Nevada are more weathered and powdery whereas they are firm, brittle and crumbly at sites in Oregon. The Oregon and Nevada populations are similar genetically, so it is probable that differences in plant vigor are related to the habitat and resources available (Kaye et al. 1990).
At first glance, populations of Eriogonum crosbyae in Oregon appear to be healthy as there are many mature, flowering plants. However, there are relatively few seedlings observed and low seedling survival means that the populations may be vulnerable to disturbances and short-term decline. In order to maintain population numbers, infrequent "good" years for seedling recruitment must have occurred in the past (Kaye et al. 1990).
Observed seed set has also been very low, especially in Oregon. Possible reasons for this low seed set include resource limitation (i.e.. Drought-perhaps there is good seed set in wetter years) and "genetic load," (causing embryo abortion due to lethal alleles in the embryo). This is common in older plants with high genetic variability and an out-crossing breeding system. |
Threats
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Cattle grazing and rabbit herbivory. (Meinke 1982).
Range improvement projects (Meinke 1982).
Off-road vehicle traffic. (Meinke 1982).
Mineral exploration and extraction (NNHP 2001).
Private property development (NNHP 2001).
Poor seed set and low seedling recruitment (Kaye et a1. 1990). |
Current Research Summary
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Germination trials at The Berry Botanic Garden. 40% germination was obtained by direct placement in a 68°F (20°C) chamber. Alternating 50°F/69°F (10°/20°C) temperatures yielded 20% germination. When seeds were first cold stratified for 8 weeks, 20% germinated in the 68°F (20°C) chamber and none germinated in the alternating 50°F/69°F (10°/20°C) chamber (BBG File).
Germination trials (Florance 1994).
Pollinators were observed and identified. Insect visitors appeared to be relatively faithful to Eriogonum crosbyae and were not observed visiting nearby closely-related species such as E. prociduum and E. ovalifolium (Kaye et al. 1990).
Eriogonum crosbyae and E. prociduum were compared using 14 morphological characteristics. They are very similar morphologically. Five traits were consistent and useful in distinguishing the two species. Some traits varied between populations of the same species (Kaye et al. 1990).
Genetic analysis utilizing isozymes to detect if Eriogonum crosbyae and E. prociduum have hybridized, to detect the amount of genetic diversity within and between populations of the same species, and to determine if such genetic analysis could be an effective method of distinguishing the two species. There was no evidence of hybridization, however, there were no alleles that were unique to any one species, so results were not definitive. Researchers found relatively high genetic diversity in E. crosbyae compared to other plant species (Kaye et al. 1990). |
Current Management Summary
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Seeds collected from 4 locations stored at the Berry Botanic Garden.
Inventories conducted in 1989 throughout the known range in Oregon resulted in no new sites (Kaye et al. 1990).
Species management guide drafted and finalized in 1989.
Several sites on land designated as an Area of Critical Environmental Concern (ACEC) managed by the Bureau of Land Management (Surprise Valley BLM).
Transplantation for mitigation and restoration project at a mine site where they would have otherwise been destroyed. Transplants were largely successful. Descriptive signage was installed to inform visitors. Plants were monitored from 1988 to 1993 (Surprise Valley BLM).
Fencing and signage to prevent disturbance of habitat by vehicles and heavy mining equipment at a nearby mining pit (Surprise Valley BLM). |
Research Management Needs
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Research the reasons for low seed set. Pollination studies, embryo dissections, and genetic studies should be employed (Kaye et al. 1990).
Conduct genetic studies to determine the mechanisms that give this species relatively high genetic diversity (Kaye et al. 1990).
Preserve large populations rather than many small populations to preserve the inherent genetic diversity (Kay et al. 1990).
Conduct long-term monitoring to detect long-term seed production trends and seedling recruitment over time (Kaye et al. 1990).
Suggest emergency listing under the Endangered Species Act if mining operations directly threaten large numbers of plants (Kaye et al. 1990). |
Ex Situ Needs
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Collect and store seeds from across the range.
Determine optimum germination requirements.
Determine propagation and reintroduction protocols. |
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Books (Single Authors)
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Meinke, R.J. 1982. Threatened and Endangered Vascular Plants of Oregon: An Illustrated Guide. Portland, Oregon: U.S. Fish & Wildlife Service, Region 1. 326p.
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ONHP. 2001. Rare, Threatened and Endangered Plants and Animals of Oregon.
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Electronic Sources
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BLM. (2002). Crosby's buckwheat (Eriogonum crosbyae). [Web site] Bureau of Land Management, Surprise Field Office. http://www.ca.blm.gov/surprise/surpercr.html. Accessed: 2002.
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NNHP. (2001). Detailed Rare Plant and Lichen Lists. Nevada Natural Heritage Program. http://www.state.nv.us/nvnhp/selists.htm. Accessed: 2002.
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NNHP. (2001). Habitat for Rare Species. Nevada Natural Heritage Program. Department of Conservation and Natural Resources.
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ONHDB. (2000). Oregon Natural Heritage Program Database. Portland, Oregon.
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Journal Articles
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Hartman, R.L.; Nelson, B.E. 1998. Novelties from North America north of Mexico: A 20-Year Vascular Plant Diversity Baseline. 51 pp.
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James, M.L.; Zedler, J. 2000. Dynamics of wetland and upland subshrubs at the salt marsh-coastal sage scrub ecotone. American Midland Naturalist. 143, 2: 298-311.
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Kaye, T.N. 1991. Chromosome numbers for Eriogonum crosbyae, E. prociduum, Ivesia baileyi var. beneolens, and I. rhypara var. shellyi. International Order of Plant Biosystematists Newsletter. 17
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Perez, C.J.; Waller, S.S.; Moser, L.W. 1998. Seedbank characteristics of a nebraska sandhills prairie. Journal of Range Management. 51, 1: 55-62.
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Reveal, J.L. 1981. Notes on endangered buckwheats (Eriogonum: Polygonaceae) with three newly described from the western United States. Brittonia. 33, 3: 441- 448.
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Reveal, J.L. 1985. New Nevada entities and combinations in Eriogonum (Polygonaceae). Great Basin Naturalist. 45: 276-280.
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Richardson, C.A.; Henderson, D.M. 1999. Classification and ordination of the alpine plant communities of Railroad Ridge, White Cloud Peaks, Idaho. Great Basin Naturalist. 59, 1: 63-78.
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Schoolcraft, G.; Tiehm, A. 1985. Noteworthy collections, Nevada. Madroρo. 32: 123-124.
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Reports
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Florance, E.R. 1994. Germination, Dormancy, and Structure of Seeds From Rare and Endangered Plant Species in Oregon. Unpublished Final Report. Cooperative Challenge Cost-Share Project funded by Bureau of Land Management and Lewis and Clark College.
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Kaye, T.; Messinger, W.; Massey, S.; Kephart, S.; Flanagan, D. 1990. Eriogonum crosbyae and E. prociduum inventory, reproduction, and taxonomic assessment. Salem, OR: Conservation Biology Program, Oregon Department of Agriculture. p.49. OSDA/BLM Challenge Cost Share Project Number 89-6.
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NNHP. 2001. Nevada Rare Plant Atlas: Index to Maps and Fact Sheets. Portland, Oregon and Reno, Nevada: Carson City: Nevada Natural Heritage Program, compiled for the U.S. Department of the Interior, Fish and Wildlife Service. Grant EP-3-12.
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Schoolcraft, G. 1989. Species management guide for Eriogonum crosbyae. Susanville, California: Bureau of Land Management.
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Smith, F.J.; Schoolcraft, G. 1989. Status Report: Eriogonum crosbyae. Susanville, California: Bureau of Land Management.
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This
profile was updated on 7/8/2010 |
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