Eriogonum pelinophilum
Author: Reveal

Clay-loving wild buckwheat

Polygonaceae (Buckwheat Family)

Close up of Eriogonum pelinophilum by Lori Brummer
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Close up of Eriogonum pelinophilum by Alicia Langton
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Close up of Eriogonum pelinophilum by Lori Brummer
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Ranks and Status

Global rank: G2
State rank: S2
Federal protection status: USFWS Endangered
State protection status: None

[+] Description and Phenology

Eriogonum pelinophilum by Vicky MacWilliam. Please also see 1997 profile.
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General description: Low rounded heavily branched pulvinate subshrubs 5-10 cm high and 8-15 cm across; lower stems light brown, woody, bark exfoliating in long loose strips or wide plates; leafless, upper branches herbaceous, slender, floccose to glabrous; leaves solitary, scattered along entire length of herbaceous stems, except for the last 5-10 mm, somewhat closely placed and congested to widely spaced, leaf blades oblanceolate, 5-12 mm long, 1-1.5 mm wide, densely white-tomentose below, midveins totally obscured by the tomentum, subglabrous to glabrous and green above, margins entire, revolute and completely enclosing the lower surface, apices and bases acute, leaves persistent, petioles 1 mm long, light yellowish-brown to tan and thinly pubescent when young, becoming glabrous; flowering stems slender, 5-10 mm long, floccose to glabrous; inflorescence cymose, +/- compact and congested, 1-2 cm long and wide, trichotomous, rays 2-5 mm long, floccose to glabrous without, thinly tormentose within, connate at base; peduncles, when present, 1-1.5 mm long, floccose to glabrous, erect; involucres solitary, narrowly turbinate, 3-3.5 mm long, 1-1.5 mm wide, floccose to glabrous without, glabrous within, 5 acute lobes 0.3-0.4 mm long, bractlets oblanceolate, 1.8-2.5 mm long, minutely fringed with capitate gland-shaped cells, pedicels 2.5-4.5 mm long, glabrous; flowers white with reddish-brown midribs and brownish-red bases, 3-3.5 mm long, glabrous within and without except for microscopic glands along the midribs within, tepals similar; achenes 3-3.5 mm long (Peterson 1982).

Look Alikes: Eriogonum contortum has yellow flowers and occurs further north (Mesa and Garfield Cos.). Eriogonum clavellatum is taller (1-2 dm), has larger involucres (4-4.5 mm long), and is only known from Montezuma Co. (Spackman et al. 1997).

Phenology: Flowering occurs from mid June to late July, and fruiting in August.

[+] Habitat

Habitat of Eriogonum pelinophilum by Alicia Langton
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Habitat of Eriogonum pelinophilum by Lori Brummer
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Eriogonum pelinophilum is found in substrates derived from the Mancos Formation shales. The entire area is typified by rolling adobe (clay) hills and flats. Generally, the plants are found in a sharply defined soil microhabitat with shadscale (Atriplex confertifolia), on mid to lower slopes of the hills. The soil types are part of the Billings Series, known for its fine texture and weak and unstable structure. These soils are calcareous throughout and in some places have visible accumulations of calcium carbonate or calcium sulfate (Cline et al. 1967). Steeper barren slopes (badlands) are above, with flatlands below dominated by mat saltbush (A. corrugata) (Cline et al. 1967, U.S. Fish and Wildlife Service 1988). The change from the lower slope soils to the flatland soils is characterized by a jump in soil sulfate level (from <100 ppm to 1650 ppm) and sodium level (Potter et. al. 1985). Clay soils have a high water holding capacity, but this moisture is not readily available to plants (Barbour et. al. 1980, cit. in O'Kane 1985). Rainfall in the E. pelinophilum habitat averages 7-10 inches annually, further contributing to the low moisture availability (Colorado Climate Center 1984). Eriogonum pelinophilum generally prefers swales and bottoms where useable moisture is more available (O'Kane 1985). Because of the low moisture availability, communities in which E. pelinophilum occur are characterized by low species diversity, low productivity and minimal canopy cover. Eriogonum pelinophilum is codominant with other xerophytic shrubs or subshrubs such as shadscale, the rare Penstemon retrorsus, Castle Valley clover (Atriplex cuneata), mat saltbush, black sagebrush (Artemesia nova) and Xylorhiza venusta (Neely 1985, O'Kane 1985). The communities are apparently stable, climax associations, judging from the lack of invading species capable of dominating the sites. Field observations indicate that the species is most abundant where biological soil crust cover is not extensive (Ferguson 2007).

Elevation Range: 5,220 - 6,378 feet (1,591 - 1,944 meters)

[+] Distribution

Distribution of Eriogonum pelinophilum in Colorado.
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Colorado endemic: Yes
Global range: Known from Delta and Montrose counties, Colorado. Estimated range is 420 square kilometers, calculated in 2008 by the Colorado Natural Heritage Program in GIS by drawing a minimum convex polygon around the known occurrences. Imprecisely reported occurrences are not included.

[+] Threats and Management Issues

Summary results of an analysis of the status of Eriogonum pelinophilum based on several ranking factors. This species was concluded to be "under conserved”. From Rondeau et al. 2011.
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Fragmentation of Eriogonum pelinophilum habitat into small units of possibly nonviable population size is the greatest threat at this time (U.S. Fish and Wildlife Service 1988). Habitats are being destroyed by rapid encroachment of irrigated agricultural land and residential development. Known occurrences are reported to be extirpated or have undergone recent degradation due to residential development (Reveal 2003). Subsequent impacts such as road building and off-road vehicle use are also significant threats. A large portion of the critical habitat type is on public land and is not in danger of being developed. However, due to the close proximity of human development, many of these sites suffer from right-of-way access, off-road vehicle use and overgrazing. These activities not only endanger known populations, but also damage or destroy potential habitat recovery areas. Other threats include gas and oil exploration, pipelines and new irrigation canals, which often skirt the bases of the adobe hills, potentially interfering with E. pelinophilum habitats (Neeley 1985, O'Kane 1985, U.S. Fish and Wildlife Service 1988).

[+] References

    • Ackerfield, J. 2012. The Flora of Colorado. Colorado State University Herbarium. 433 pp.
    • Barbour, M.G., J.H. Burke, and W.D. Pitts. 1980. Terrestrial Plant Ecology. Benjamin/Cummings Pub. Co., Inc. Menlo Park, CA.
    • Bowlin, W.R.,V.J. Tepedino, and T.L. Griswold. 1993. The reproductive biology of Eriogonum pelinophilum (Polygonaceae). Pages 296-302 in R. Sivinski and K. Lightfoot, editors. Southwestern rare and endangered plants. New Mexico Energy, Minerals and Natural Resources Department, Forestry and Resources Conservation Division, Miscellaneous Publication Number 2.
    • Bureau of Land Management (BLM). 1988. Uncompahgre Basin Proposed Resource Management Plan and Final Environmental Impact Statement. Department of the Interior, Colorado State Office, Montrose District. 195pp.
    • Bureau of Land Management (BLM). 1989. Uncompahgre Basin Resource Management Plan and Record of Decision. U.S. Department of the Interior, Colorado State Office, Montrose District. 56pp.
    • Bureau of Land Management. 2003. Environmental Assessment Record for Eriogonum pelinophilum.
    • Carpenter, A. and T. Schultz. 1994. Population Dynamics, Growth and Reproduction of the Clay-loving Wild Buckwheat (Eriogonum pelinophilum) at Wacker Ranch in Montrose County, Colorado.
    • Cline, A.J., Spears, F. Mehaffey, E. Kubin, R. Franklin and C. Pachek. 1967. Soil Survey of the Delta-Montrose Area, Colorado. U.S. Department of Agriculture - Soil Conservation Service. U.S. Government Printing Office, Washington, D.C. 73pp.
    • Coles, J. 2003. Personal communication with Colorado Natural Heritage Program.
    • Colorado Climate Center. 1984. Colorado Average Annual Precipitation 1951-1980. Colorado State University, Ft. Collins.
    • Colorado Native Plant Society. 1989. Rare plants of Colorado. Rocky Mountain Nature Association, Colorado Native Plant Society, Estes Park, Colorado. 73 pp.
    • Colorado Natural Areas Program (CNAP). Life History Characterisitics and Habitat Requirements for ERIOGONUM PELINOPHILUM and Protection of Known Populations; 3 reports: i) Program Narrative, Undated ii) Performance Report 1987 iii) Performance Report 1988. All unpublished.
    • Elliott, B. A., S. Spackman Panjabi, B. Kurzel, B. Neely, R. Rondeau, M. Ewing. 2009. Recommended Best Management Practices for Plants of Concern. Practices developed to reduce the impacts of oil and gas development activities to plants of concern. Unpublished report prepared by the Rare Plant Conservation Initiative for the National Fish and Wildlife Foundation.
    • Ferguson, J. 2003. Personal communication with CNHP staff.
    • Ferguson, J. 2007. Summer 2007 Clay-Loving Wild Buckwheat (Eriogonum pelinophilum) Field Surveys, Including an Assessment of the Potential Effects of Livestock Grazing on this Species within the Colona LHA.
    • Flora of North America Editorial Committee. 2005. Flora of North America North of Mexico. Vol. 5. Magnoliophyta: Caryophyllidae: Caryophyllales, Polygonales, and Plumbaginales. Oxford Univ. Press, New York. vii + 656 pp.
    • Graham, S. 1984 July 18. Delta plant declared endangered. Rocky Mountain News.
    • Kartesz, J. T. 1999. Comments regarding taxa 1-187 [of list supplied by TNC]. Unpublished, Biota of North America Program, North Carolina Botanical Garden, Chapel Hill, N.C., Nov. 25, 1999.
    • Kartesz, J.T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. 2nd edition. 2 vols. Timber Press, Portland, OR.
    • Kartesz, J.T. 1999. A synonymized checklist and atlas with biological attributes for the vascular flora of the United States, Canada, and Greenland. First edition. In: Kartesz, J.T., and C.A. Meacham. Synthesis of the North American Flora, Version 1.0. North Carolina Botanical Garden, Chapel Hill, N.C.
    • Lyon, P. 2003. Personal communication with Colorado Natural Heritage Program.
    • Lyon, P. 2008. Monitoring of Eriogonum pelinophilum at the Wacker Ranch, Montrose, Colorado.
    • Mueller-Dumbois, D. and H. Ellenberg. 1974. Aims and Methods of Vegetation Ecology. Wiley and Sons, Inc.
    • NatureServe. Unpublished. Concept reference for taxa for which no reference which describes the circumscription has been recorded; to be used as a placeholder until such a citation is identified.
    • Neely, B., S. Panjabi, E. Lane, P. Lewis, C. Dawson, A. Kratz, B. Kurzel, T. Hogan, J. Handwerk, S. Krishnan, J. Neale, and N. Ripley. 2009. Colorado Rare Plant Conservation Strategy, Developed by the Colorado Rare Plant conservation Initiative. The Nature Conservancy, Boulder, Colorado, 117 pp.
    • Neely, E.E. 1985. Site Conservation Summary for Wacker's Ranch. Unpublished report for the Nature Conservancy, Boulder, Colorado.
    • O'Kane, S. L., Jr. 1985. Endangered Species Information System, Species Biology Workbook for ERIOGONUM PELINOPHILUM. U.S. Fish and Wildlife Service.
    • O'Kane, S.L. 1988. Colorado's rare flora. Great Basin Naturalist 48(4): 434-484.
    • Potter, L. D., R. C. Reynolds, and E. T. Louderbough. 1985. Mancos shale and plant community relationships: Analysis of shale, soil, and vegetation transects. Journal of Arid Environments 9:147-165.
    • Potter, L.D., R.C. Reynolds Jr., and E.T. Louderbaugh. 1985. Mancos Shale and plant community relationships: field observations. Journal of Arid Environments. 9:137-145.
    • Reveal, J. 2003. Personal communiction with Colorado Natural Heritage Program.
    • Reveal, J.L. 2006. On the Status of Eriogonum pelinophilum Reveal (Polygonaceae Juss.: subf. Eriogonoideae Arn.)
    • Reveal, James L. 1973. A new subfruticose Eriogonum (Polygonaceae) from western Colorado. Great Basin Naturalist. 33:120-2.
    • Rocky Mountain Society of Botanical Artists. 2009. RARE Imperiled Plants of Colorado, a traveling art exhibition. Exhibition catalogue developed by the Denver Botanic Gardens and Steamboat Art Museum.
    • Spackman, S., B. Jennings, J. Coles, C. Dawson, M. Minton, A. Kratz, and C. Spurrier. 1997. Colorado rare plant field guide. Prepared for Bureau of Land Management, U.S. Forest Service and U.S. Fish and Wildlife Service by Colorado Natural Heritage Program.
    • Spinks, J. 1991. Clay loving wild buckwheat recovery plan. Unpublished report prepared for the US Fish and Wildlife Service.
    • U.S. Fish and Wildlife Service (USFWS). 1988. Clay-loving Wild-buckwheat Recovery Plan. U.S. Fish and Wildlife Service, Denver, Colorado.
    • U.S. Fish and Wildlife Service. 1984. Final rule to determine Eriogonum pelinophilum to be an endangered species. Federal Register 49(136): 28562-28565.
    • USDA, NRCS. 2013. The PLANTS Database. National Plant Data Team, Greensboro, NC 27401-4901 USA.
    • Weber, W. A. and R. C. Wittmann. 2012. Colorado Flora, Western Slope, A Field Guide to the Vascular Plants, Fourth Edition. Boulder, Colorado. 532 pp.
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    • West, R. 2003. Personal commuication with CNHP staff.

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