Hawkweed wild buckwheat

Eriogonum leucophyllum Wooton & Standley subsp. pannosum (Wooton & Standley) S. Stokes; Pterogonum hieracifolium (Bentham) H. Gross

Herbs, polycarpic, 4-7 dm, strigose; taproot not chambered. Stems: caudex compact; aerial flowering stems usually 2-5, not fistulose, 3.5-5.5 dm, strigose. Leaves basal and cauline; basal petiolate, petiole 0.5-5 cm, strigose, blade oblanceolate to spatulate, 3-15 × 0.5-2(-2.5) cm, sparsely to densely strigose on both surfaces; cauline sessile, blade oblanceolate, 0.5-5(-6) × 0.3-1 cm, similar to basal blade.  Inflorescences 0.4-1.5(-1.8) dm; branches strigose; bracts scalelike, 2-8 × 1-3 mm. Peduncles erect, straight, 0.5-3(-3.5) cm, strigose. Involucres turbinate-campanulate to campanulate, 2.5-4 × 2.5-5 mm, hirsute to strigose; teeth 0.5-1.5 mm. Flowers 1.5-2.5 mm in anthesis, 3-5 mm in fruit; perianth yellow in anthesis, reddish in fruit, pilose abaxially; tepals narrowly ovate; stamens 2-3 mm; filaments pilose proximally. Achenes yellowish green to light brown, 4.5-6 mm, strigose, 3-winged along distal 2, nearly beakless. 2n = 40.

Flowering Jun-Oct. Sandy to gravelly, often calcareous flats and slopes, grassland, saltbush, creosote bush, and mesquite communities, oak, juniper, and montane conifer woodlands; (900-)1300-2600 m; Ariz., N.Mex., Tex.; Mexico (Chihuahua).

Eriogonum hieracifolium is widely scattered from east-central Arizona (Apache, Gila, Graham, and Navajo counties) and adjacent west-central and southern New Mexico (Bernalillo, Catron, Dona Ana, Eddy, Grant, Lincoln, Otero, and Sierra counties) into Texas (Brewster, Culberson, Jeff Davis, Pecos, and Presidio counties). The species occurs in northeastern Chihuahua, Mexico, as well. Similar plants found near La Linda in Coahuila appear to represent a different taxon, as their vegetative structures are tomentose rather than strigose.