Brandegee's wild buckwheat

Eriogonum spathulatum A. Gray var. brandegeei (Rydberg) S. Stokes

Herbs, spreading, sometimes scapose, 1-2.5 × (0.5-)1-2 dm, tomentose to floccose, grayish. Stems spreading, with persistent leaf bases, up to 1/ 4 height of plant; caudex stems matted, floccose or glabrous; aerial flowering stems erect, slender, solid, not fistulose, 1-2.5 dm, tomentose to floccose. Leaves strictly basal, 1 per node; petiole 1-3(-3.5) cm, lanate; blade oblanceolate to elliptic, 1.5-4(-5) × 0.4-1.2(-1.6) cm, densely white-tomentose adaxially, less so and greenish adaxially, margins plane. Inflorescences capitate or umbellate-cymose, 0.1-1.5 cm wide, tomentose to floccose; branches dichotomous, sometimes absent, tomentose to floccose; bracts 3, scalelike, triangular, and 2-5 mm, or leaflike, lanceolate, and 1-3 × 0.2-0.7 cm. Peduncles absent. Involucres 4-8 per cluster, turbinate, 3.5-5 × 3-4 mm, floccose or glabrous; teeth 5, erect, 0.4-0.8 mm. Flowers (2.5-)3-3.5 mm; perianth ochroleucous, glabrous; tepals connate proximal 1/ 4, monomorphic, oblanceolate to oblong; stamens exserted, 3-3.5 mm; filaments pilose basally. Achenes light brown, 3-3.5 mm, glabrous.

Flowering Jul-Oct. Clay slopes and washes, sagebrush communities, juniper woodlands; of conservation concern; 1800-2600 m; Colo.

Eriogonum brandegeei is a rare and localized species known from nine occurrences along the Arkansas River in Chaffee and Fremont counties. It is regarded as a “sensitive” species in Colorado, by both the state and the U.S. Forest Service. The Droney Gulch Natural Area has been established, in part, to protect the species. Brandegee's wild buckwheat is related to E. brevicaule var. laxifolium, but well isolated from that taxon. An undated E. L. Greene specimen (ISC) supposedly was gathered in northern New Mexico, but that is most unlikely. A G. W. Letterman collection (MO) purportedly from Colorado Springs certainly is mislabeled.