Perennial herb forming hemispheric mounds up to 3 dm across from an intricately branching caudex; leaves all basal, short-petiolate, the blade narrowly elliptic, 4-12 mm long, 1.5-4 mm wide, silky-tomentose below, green and strigose above, the margins revolute; inflorescence stems up to 40 or more per plant, 1.5-5.5 cm long, silky tomentose; inflorescences capitate; involucres 5-lobed, 3-5 mm high, 5-6.5 mm wide; flowers yellow, 2.5-4.5 mm long, 5-12 per involucre; petals villous pubescent on outer surface; ovaries and seeds villous. Flowers late May and June.
Eriogonum lachnogynum is distinguished from other perennial yellow-flowered wild buckwheats in New Mexico by its villous ovaries and seeds. Variety lachnogynum usually has fewer and longer flowering stems with broader inflorescences than var. sarahiae and does not form large hemispheric mounds. Variety colobum is also a cushion-like (pulvinate) plant, but with very short inflorescences that usually do not exceed the leaves.
New Mexico, McKinley County, Chuska Mountains; Arizona, Apache and Navajo counties.
Open sandy limestone ridges and edges of mesas in piñon-juniper woodland; about 1,800-2,300 m (5,900-7,540 ft).
Sarahs wild buckwheat occurs in very small, widely scattered populations that could be seriously impacted by quarrying or road building activities. This unpalatable plant is not threatened by livestock grazing.
Atwood, N.D. and A. Clifford. Nomenclatural proposals and taxonomic novelties. Page 840, In: Welsh, S.L., N.D. Atwood, S. Goodrich and L.C. Higgins. 2003. A Utah Flora, 3rd ed. Monte L. Bean Life Science Museum, Brigham Young University, Provo, Utah.
Reveal, J.L. 2004. Nomenclatural summary of the Polygonaceae subfamily Eriogonideae. Harvard Papers in Botany 9:143-230.
Reveal, J.L. and A. Clifford. 2004. A new variety of Eriogonum lachnogynum (Polygonaceae: Eriogonideae). Phytologia 86(3):169-172.
Reveal, J.L. Eriogonum. Pages 218-430, In: Flora of North America Editorial Committee. 2005. Flora of North America, volume 5. Oxford University Press, New York.