Clay-loving wild buckwheat - USDA Plants Database

CLAY-LOVING WILD 

BUCKWHEAT 

Eriogonum pelinophilum 

Reveal 

Plant Symbol = ERPE10 

Contributed by: USDA NRCS Colorado Plant 

Materials Program 

Figure1: Clay-loving wild buckwheat, Eriogonum pelinophilum. 

Photo USFWS, Alicia Langton July 2010. 

Alternate Names 

N/A 

Uses 

Clay-loving wild buckwheat, (Eriogonum 

pelinophilum) was first collected in 1958 near 

Hotchkiss, Colorado, in Delta County by Howard 

Gentry (U.S. Fish and Wildlife Service (USFWS, 

1988). The species was first described by James 

Reveal in1973. Clay-loving wild buckwheat’s 

particularly long flowering period extends from May 

to early September with individual flowers lasting 

fewer than 3 days. Perhaps due to its extended 

flowering period or because it is the most abundant 

species in bloom in its habitat, clay-loving wild 

buckwheat flowers are visited by more than 50 

species of pollinators in a season (Bowlin et al., 

1992). Roughly half of these 50 species are native 

bees, and 18 species are native ants (USFWS, 2009). 

USFWS in its 5-year review of the species cited 

Tepedino (2011) noting that of all Eriogonum species 

studied to date, none has as many pollinators as clayloving 

wild buckwheat. 

Plant Guide 

Edible buckwheat (Fagopyrum esculentum) is an 

important food crop originating from Eurasia and is 

in the same botanical family as clay-loving wild 

buckwheat. Although the common name alludes to 

it, clay-loving wild buckwheat has no association 

with wheat or cereal grains. There are no 

agricultural, economic, or other human uses of clayloving 

wild buckwheat known at this time. 

Status 

Clay-loving wild buckwheat was designated as 

endangered, with critical habitat, by the USFWS in 

1984. In 2009, the USFWS completed a 5-year status 

review to update the status of the species. This 

review noted that the range of clay-loving wild 

buckwheat primarily stayed the same as when the 

recovery plan was completed in 1988 (USFWS, 

2009) (some sites were destroyed while new sites 

were discovered) even though increases in species 

numbers were noted (from 10,000 known individuals 

to ~278,425 known individuals). The USFWS 

attributed these changes in population to increased 

survey efforts rather than species expansion 

(USFWS, 2009). The NatureServe conservation 

status rank an international effort which rank species 

on their “global” status, denotes clay-loving wild 

buckwheat as G2/S2- globally imperiled and 

statewide imperiled, with a high risk of extinction 

due to very restricted range, very few populations 

(often 20 or fewer), steep declines, or other factors 

(NatureServe, 2011). 

Description 

General: 

Buckwheat family (Polygonaceae). Clay-loving wild 

buckwheat is a long-lived low-growing, spreading 

sub-shrub, reaching up to 4 inches (10 centimeters) in 

height and 12 in (30 cm) across (Reveal, 2005). 

“Stems are spreading without persistent leaf bases up 

to 1/3 the height of the plant; aerial flowering stems 

spreading to erect, slender, leaves, 1 per node” 

(Reveal, 2005). Leaves are dark green and appear 

needle-like with in-rolled margins (USFWS, 2009). 

Flowers are white to cream with reddish-brown 

midribs and brownish-red bases (USFWS, 2009), 

(Figure 2), petals all the same length. Fruits are 

achenes, light brown, 0.1 in (0.3 to 0.35 cm) and 

triangular in cross-section. Flowering occurs late 

May to early September.

Figure 2: Clay-loving wild buckwheat, detailing the white to 

cream flowers with reddish-brown midribs and brownish-red bases 

Photo USFWS, Alicia Langton July 2010. 

Clay-loving wild buckwheat may be distinguished 

from its close relatives E. clavellatum and E. 

contortum, according to Reveal (2005) and 

Spackman et al. (1997) as follows: 

E. clavellatum is larger in stature and habit and has 

larger flowers up to 1.8 in (4.5 cm) with petals of two 

different lengths, E. clavellatum lacks the reddishbrown 

midribs and brownish-red bases and E. 

clavellatum is known to occur only in the Four 

Corners region (Weber, 1987). Attempts to separate 

the two genetically have been inconclusive. 

E. contortum has yellow flowers and occurs farther 

north than E. pelinophilum, in Mesa and Garfield 

Counties in Colorado and in Grand County, Utah, 

(Spackman et al.,1997). 

Distribution: 

Clay-loving wild buckwheat is endemic to the rolling 

clay (adobe) hills and flats immediately adjacent to 

the communities of Delta and Montrose, of westcentral 

Colorado. According to USFWS 5-year 

review (2009), citing information based on spatial 

data tracked by the Colorado Natural Heritage 

Program in 2009, the total global population of this 

species occurs roughly within an area that is 11.5 mi 

north to south and 28.5 mi east to west. Nearly 75% 

of the existing known populations and habitat for 

clay-loving buckwheat occur on private land 

(USFWS 2009). Please consult the USFWS website 

at www.fws.gov for a map of the species occurrence. 

For current distribution, please consult the Plant 

Profile page for this species on the PLANTS Web 

site. 

Habitat: 

The habitat of clay-loving wild buckwheat consists of 

adobe clay badland hills and flats within the sparsely 

vegetated desert shrub community. This plant 

community includes the following clay-loving 

buckwheat plant associates: mat saltbush (Atriplex 

corrugata), black sagebrush (Artemesia nova), 

shadscale (Atriplex confertifolia), Gardner’s saltbush, 

(Atriplex gardneri), bud sagebrush (Picrothamnus 

desertorum), charming woodyaster, (Xylorhiza 

venusta), and Adobe Hills beardtongue (Penstemon 

retrorsus) (USFWS, 2009), (Rocky Mountain 

Herbarium, 2010). 

Adaptation 

Clay-loving wild buckwheat is adapted to the harsh 

growing conditions that include clay, alkaline, and 

calcareous soils of the Mancos shale formation, 

unique to west-central Colorado (Potter, 1985). The 

Mancos shale formation has been associated with 

high salts and selenium (USFWS, 2009), however no 

selenium accumulation information related to clayloving 

wild buckwheat is known at this time. At 

elevations ranging from 5,180 to 6,350 ft., clayloving 

wild buckwheat is generally found growing on 

the mid to lower slopes of the rolling topography of 

the adobe Mancos shale hills, also occurring in 

swales or drainages (USFWS, 2009). With an 

average annual total precipitation of 7-10 inches, 

clay-loving wild buckwheat is dependent upon the 

microclimates created by the small areas where snow 

lingers longer due to aspect, topography, and 

landscape position. 

Figure 3: Clay-loving wild buckwheat harsh site conditions. Photo 

USFWS, Alicia Langton July 2010. 

Management 

Clay-loving wild buckwheat is a long-lived species, 

as demonstrated by static populations over the last 20 

years, with recruitment of seedling plants being 

sporadic and infrequent (USFWS, 2009). Clayloving 

wild buckwheat occurrences and suitable 

habitat continue to be threatened by growing 

development pressure and related expansion activities 

around the communities where it occurs. 

Additionally, 75% of the occupied habitat occurs on 

private lands. In Colorado, endangered plant species 

are not afforded protection unless a Federal nexus 

exists, such as canal development projects. 

Conservation efforts geared toward private lands 

would greatly benefit this species to prevent further 

isolation of the small existing populations most at

isk from habitat fragmentation, thereby reducing the 

resiliency of these populations. 

Pests and Potential Problems 

Tent caterpillar impacts were noted on clay-loving 

buckwheat by Ferguson (2007). 

Environmental Concerns 

The effects of climate change could pose continued 

uncertainty to the long term survival of clay-loving 

wild buckwheat populations. Due to the limited 

range of the Mancos shale formation and the longlived 

nature of this species, its ability to migrate with 

changing climates is uncertain. Decreased or lack of 

flowering has been noted in association with the 1998 

drought in the region, thereby causing concern that a 

lack of precipitation, during the growing and 

flowering season, could significantly impact seedling 

recruitment (USFWS, 2009). 

Seeds and Plant Production 

Clay-loving wild buckwheat requires an insect 

pollinator in order to set seed, for both outcrossing 

and self-pollination (within a plant but not within a 

flower) (Bowlin et al. 1993, Tepedino et al., 2011). 

O’Kane in 1985 stated that “seed dispersal is usually 

passive, either being consumed or carried by animals, 

windblown, or moved by gravity or water.” “All 

Eriogonum species studied thus far have seeds that 

require a cold period to break dormancy (not 

necessarily a freeze), and some Eriogonum species 

have seeds with a 5-year shelf life (Reveal undated, 

cit. in O'Kane 1985).” 

According to the Colorado Natural Areas Program 

life history study of clay-loving wild buckwheat, it 

appears that this species grows at highest densities 

away from other shrubs, such as black sagebrush 

(Artemisia nova) (CNAP, 1987). Other research in 

which individuals of clay-loving wild buckwheat 

were permanently tagged from 1990 to 2008 supports 

the conclusion that this species is relatively longlived 

(20-30years minimum), (Lyon, 2008). 

References 

Brown, T. A., A. Shrift. 1982. Selenium: Toxicity 

and Tolerance in Higher Plants. Biological 

Reviews. 1982, Vol. 57, pp. 59-84. 

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. 

Cane, J.H. 2011 Personal Communication. USDA- 

ARS Pollinating Insect Research Lab 

Utah State University, Logan, UT 84322 USA. 

Chapman, S.S., G.E. Griffith, J.M. Omernik, A.B. 

Price, J. Freeouf, and D.L. Schrupp. 2006. 

Ecoregions of Colorado (color poster with map, 

descriptive text, summary tables, and 

photographs): Reston, Virginia, U.S. Geological 

Survey (map scale 1:1,200,000). 

Center for Plant Conservation. 

http://www.centerforplantconservation.org/. 

Accessed September 2011 at: 

http://www.centerforplantconservation.org/collec 

tion/CPC_ProfileImage.asp?fn=1773a. 

Colorado Natural Areas Program (CNAP). 1987. 

Life history characteristics and habitat 

requirements for Eriogonum pelinophilum (clayloving 

wild buckwheat-threatened): 1987 

performance report. Unpublished report. 

Ferguson, J.R. 2007. Summer 2007, Clay-loving 

buckwheat field surveys. Unpublished report for 

the Bureau of Land Management, Uncompahgre 

Field Office. 

Flora of North America, eFlora. Accessed June 2011 

at:http://www.efloras.org/florataxon.aspx?flora_i 

d=1&taxon_id=250060457. 

Lyon, P. 2008. Monitoring of Eriogonum 

pelinophilum at the Wacker Ranch Montrose, 

Colorado. Unpublished report prepared by the 

Colorado Natural Heritage Program, June 2008. 

NatureServe. 2011. NatureServe. (2011). 

NatureServe Explorer: An online encyclopedia 

of life [web application]. Version 7.1. 

NatureServe, Arlington, Virginia. Available 

http://www.natureserve.org/explorer. (Accessed: 

September 25, 2011 ). 

O'Kane, S. L. 1988. Colorado's Rare Flora. Great 

Basin Naturalist. 48(4):434-484. 

O'Kane, S. L. Jr. 1985. Endangered Species 

Information System, Species Biology Workbook 

for Eriogonum pelinophilum. U.S. Fish and 

Wildlife Service. 

Potter, L.D.; R.C. Jr. Reynolds, E.T. Louderbough, 

1985. Mancos Shale and plant community 

relationships: field observations. Journal of Arid 

Environments. 9: 137-145. 

Reveal, J.L. 2005. Flora of North America, 

www.eFloras.org: Eriogonum. Accessed on the 

internet May1, 2011. 

Rocky Mountain Herbarium. www.rhm.uwyo.edu, 

3/25/2010. Accessed July 2011, E. pelinophilum 

accession information on database. 

Spackman, S., B. Jennings, J. Coles, C. Dawson, M. 

Minton, A. Kratz, and C. Spurrier. 1997. 

Colorado Rare Plant Field Guide. Prepared for 

the Bureau of Land Management, the U.S. Forest 

Service and the U.S. Fish and Wildlife Service 

by the Colorado Natural Heritage Program. 

Tepedino, V.J., W.R. Bowlin, and T.L.Griswold. 

2011. Diversity and Pollination Value of Insects 

Visiting the Flowers of a Rare Buckwheat 

(Eriogonum pelinophilum: Polygonaceae) in

Disturbed and “Natural” Areas. Journal of 

Pollination Ecology, 4(8), 2011, pp57-67. 

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 (USFWS). 1984. Final 

rule to determine Eriogonum pelinophilum to be 

an endangered species. Federal Register 49(136): 

28562-28565. 

U.S. Fish and Wildlife Service (USFWS). 2009. 

Clay-loving Wild-buckwheat 5-year Review. 

U.S. Fish and Wildlife Service, Denver, 

Colorado. 

USDA, Natural Resources Conservation Service, 

PLANTS Database [USDA PLANTS]. 

http://plants.usda.gov/. Accessed 2011. 

Weber, W.A. 1987. Colorado Flora: Western Slope. 

Colorado Associated University Press, Boulder, 

Colorado. 530pp. 

Acknowledgements: 

Thank you for editorial and photo contributions from: 

Anderson, David and the Botany Team with the 

Colorado Natural Heritage Program, CSU, Fort 

Collins, Co. 

Denver Botanic Garden, Herbarium. Denver, Co. 

Cane, Jim. USDA-ARS Pollinating Insect Research 

Lab Utah State University, Logan, UT 

Lederer, N. University of Colorado Herbarium, 

Boulder, Co. 

Nelson, E. Rocky Mountain Herbarium. University 

of Wyoming, Laramie, WY. 

O’Kane, Steve L. Jr. University of Northern Iowa, 

Cedar Falls, IA. 

Prepared By: 

Christine Taliga, USDA NRCS Colorado State 

Office, Denver, Co., and Gina Glenne, USFWS, 

Mountain-Prairie Region, Grand Junction, Colorado. 

Citation 

Taliga, Christine E., Glenne, Gina, 2011. Plant Guide 

for clay-loving wild buckwheat (Eriogonum 

pelinophilum). USDA-Natural Resources 

Conservation Service, Colorado State Office. 

Denver, CO 80225-0426. 

Published September, 2011 

Edited: 18Sep2011 cet; 22Sep2011 fws, 22Sep2011 

jab, 22Sep2011cnhp, 23 Sep2011cga, 23Sep2011jsj 

For more information about this and other plants, 

please contact your local NRCS field office or 

Conservation District at http://www.nrcs.usda.gov/ 

and visit the PLANTS Web site at 

http://plants.usda.gov/ or the Plant Materials Program 

Web site http://plant-materials.nrcs.usda.gov. 

PLANTS is not responsible for the content or 

availability of other Web sites. 

USDA IS AN EQUAL OPPORTUNITY PROVIDER AND EMPLOYER

Clay-loving wild buckwheat - USDA Plants Database

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