Clay-loving Wild-buckwheat

Eriogonum pelinophilum

Description

Clay-loving wild buckwheat, Eriogonum pelinophilum, is a low-growing, rounded subshrub, about 4 in (10 cm) high and 6 in (15 cm) across, with woody stems at the base and herbaceous stems above. Narrow leaves, 0.5 in (1.2 cm) long, are dark green above and densely woolly below. Clusters of small off-white flowers appear at ends of the herbaceous branches in spring.

Habitat

This plant grows in alkaline white clay soils, locally referred to as adobes, of rugged semi-arid badlands. It is restricted to clay outcrops that are derived from Mancos shale.

Distribution

While never very widespread because of the limited occurrence of its favored soil, clay-loving wild buckwheat was once more abundant in west-central Colorado in Delta and Montrose counties.

The largest population of this plant consists of two colonies about 1 mi (1.6 km) apart on 120 acres (49 hectares) of privately-owned ranchland. Plants grow on bluffs that rise above the Gunnison River Valley in Delta County between Austin and Hotchkiss. The population at this site numbered about 10,000 plants when the species was federally listed in 1984.

Field work conducted by the Colorado Natural Heritage Inventory in 1984 located six smaller populations of wild buckwheat in Delta and Montrose counties. These populations appeared to have been reduced and isolated by conversion of the surrounding land to agricultural uses.

Threats

Although the region is marginally suited to grazing, land between the two colonies has been fenced for horse corrals and pastures. Within fenced areas, the animals have at least partially denuded native vegetation by grazing and trampling, and weedy, common plants have sprung up instead. Buckwheat populations are under imminent threat of being fenced in the same way, an act that would probably eradicate the species. In addition, pasture management requires some use of off-road vehicles, which has destroyed plants.

Conservation and Recovery

Critical Habitat for the species was designated to include the entire current range, as well as the band of soil preferred by this species, to allow for future expansion of the population. A designation of Critical Habitat protects the plant from disturbance caused by federal agencies, but the entire area is privately owned.

Contact

Regional Office of Endangered Species
U.S. Fish and Wildlife Service
P.O. Box 25486
Denver Federal Center
Denver, Colorado 80225
http://www.r6.fws.gov/

References

Reveal, J. L. 1971. "Notes on Eriogonum-VI: A Revision of the Eriogonum microthecum Complex (Polygonaceae)." Brigham Young University Science Bulletin, Biological Series 13(1):1-45.

Reveal, J. L. 1973. "A New Subfruticose Eriogonum (Polygonaceae) from Western Colorado." Great Basin Naturalist 33:120-122.