Tall wild buckwheat

Plants 1-5 dm. Caudex stems compact. Leaves basal; blade usually elliptic, 0.3-1.5 × 0.3-1 cm. 2n = 40.

Flowering May-Nov. Sandy to gravelly flats and slopes, mixed grassland, saltbush, creosote bush, mesquite, and sagebrush communities, oak and conifer woodlands; 900-2200 m; Colo., N.Mex., Okla., Tex.; Mexico (Chihuahua, Coahuila).

Variety tenellum is common and widespread throughout its northern range in southeastern Colorado, New Mexico, western Oklahoma, and northern and western Texas. Outlying populations, extending northward from Mexico, enter the flora area in Dona Ana County, New Mexico, and Webb County, Texas.