Pterogonum alatum (Torrey) H. Gross

Herbs, monocarpic, 5-20(-25) dm, strigose or glabrous; taproot often chambered. Stems: caudex absent; aerial flowering stems usually 1, not fistulose, 2-13 dm, strigose or glabrous. Leaves basal and sometimes cauline; basal petiolate, petiole 2-6 cm, stigose to woolly or glabrous, blade linear-lanceolate or lanceolate to oblanceolate to spatulate, (3-)5-20 × 0.3-2 cm, strigose, becoming glabrous and green on both surfaces except for margins and midvein; cauline sessile, blade linear-oblanceolate to lanceolate, 1-9 × 0.3-0.8(-1) cm, similar to basal blade. Inflorescences 2-10 dm; branches strigose or glabrous; bracts semileaflike proximally, linear to linear-lanceolate, 2-9 × 1-3 mm, scalelike distally, triangular, 0.8-5 × 0.5-2 mm. Peduncles erect, straight or curving upward, 0.5-3.5 cm, strigose or glabrous. Involucres turbinate to campanulate, 2-4(-4.5) × 2-4(-4.5) mm, strigose or glabrous; teeth 1-1.8 mm. Flowers 1.5-2.5 mm in anthesis, 3-6 mm in fruit; perianth yellow to yellowish green, rarely maroon in anthesis, often reddish or maroon in fruit, glabrous; tepals lanceolate; stamens 1.5-3 mm; filaments glabrous. Achenes yellowish green to reddish brown, 5-9 mm, glabrous, 3-winged entire length, beakless.

Varieties 2 (2 in the flora): w North America, including Mexico.

The mature reddish roots of Eriogonum alatum can be distinctively chambered. The Navajo (Diné) people consider the species to be a “life medicine” (L. C. Wyman and S. K. Harris 1951), using a mixture of shredded roots and water primarily to treat internal ailments. The species is used also as a ceremonial medicine (P. A. Vestal 1952). The Zuni use it as an emetic for stomachaches (S. Camazine and R. A. Bye 1980).