Cacalia decomposita A. Gray, Smithsonian Contr. Knowl. 5(6): 99. 1853; Mesadenia decomposita (A. Gray) Standley; Odontotrichum decompositum (A. Gray) Rydberg

Perennials; caudices thick, tough. Stems subscapiform, densely hairy proximally, sparsely hairy to subglabrous distally. Leaves mostly basal; petiole lengths ± equaling blades; blades ovate or elliptic, 20–30(–40) cm, nearly as wide, deeply 3–4-pinnatisect, ultimate lobes narrowly triangular to oblong, acute; mid and distal leaves progressively smaller, bractlike. Calyculi: bractlets 2–4 mm. Phyllaries (4–)5–7 mm. Corollas 7–9 mm. Cypselae 4–5 mm; pappi 4–7 mm. 2n = 60.

Flowering summer–early fall. Shady sites, open woodlands; 1700–2600 m; Ariz., N.Mex.; Mexico (Chihuahua, Durango, Sonora).

Psacalium decompositum barely enters the flora area in Arizona and New Mexico.