Kidney-shaped wild buckwheat

Eriogonum filicaule S. Stokes

Herbs, erect or slight spreading, annual, 1-5(-7) dm, mostly glabrous, usually greenish. Stems: caudex absent; aerial flowering stems erect, solid, not fistulose, (0.2-)0.5-1.5 dm, glabrous except floccose to glabrescent proximally. Leaves basal; petiole (1-)2-6 cm, mostly floccose; blade reniform to orbiculate, (0.3-)1-3.5(-4) × (0.3-)1-4(-5) cm, densely white-tomentose abaxially, hirsute to floccose or glabrous and greenish adaxially, margins plane. Inflorescences cymose, open to somewhat diffuse, 5-40(-50) × 5-35 cm; branches glabrous; bracts 3, scalelike, 1-3 × 1.5-2.5 mm. Peduncles erect or nearly so, straight, filiform, 0.5-2.5 cm, glabrous or rarely floccose at or before anthesis. Involucres turbinate, 0.5-1 × 0.6-0.9 mm, glabrous; teeth 5, erect, 0.2-0.4 mm. Flowers 0.6-1.6(-2) mm; perianth white to rose or rarely yellowish, glabrous or puberulent to sparsely hirsute; tepals monomorphic, lanceolate to spatulate or elliptic to ovate; stamens included to slightly exserted, 0.7-1.4 mm; filaments glabrous. Achenes light to dark brown, 3-gonous, 1.7-2 mm, glabrous.

Flowering Apr-Oct. Sandy to gypsophilous or clayey flats and slopes, saltbush, greasewood, blackbrush, and creosote bush communities, oak and pinyon-juniper woodlands; 800-2100 m; Ariz., N.Mex., Utah.

Eriogonum subreniforme is generally rare to infrequent throughout its scattered range in northern Arizona (Apache, Coconino, Mohave, and Navajo counties), northwestern New Mexico (McKinley and San Juan counties), and southern Utah (Garfield, Kane, and Washington counties). Even in a “good” year, the plants are rarely common and never weedy.