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.
FNA 2006, Kearney and Peebles 1969, McDougall 1973
Duration: Perennial Nativity: Native Lifeform: Subshrub General: Herbaceous perennials, to 1 m tall, stems wooly tufted at the base, otherwise herbage glabrous, plants with thick, tough caudices. Leaves: Opposite or alternate, 3-4 times pinnasect into linear segments, ultimate lobes triangular to oblong, occurring mostly in a basal tuft, long-petioled, cauline leaves few, reduced. Flowers: Heads radiate, with 5-7 white florets, involucres turbinate, row of bracts around outer calyx 2-4 mm, phyllaries 5-6 in a single series, these less than half as long as the flowers, the heads small, numerous, borne in dense, terminal corymbiform panicles. Fruits: Achenes glabrous, 4-5 mm. Pappus of numerous capillary bristles, 4-7 mm. Ecology: Found in rich, shaded soils, in open woodlands, from 5,000-8,000 ft (1524-2438 m); flowering July-September. Distribution: Arizona, New Mexico; Mexico. Notes: Look for this species under Cacalia decomposita in the older texts. Ethnobotany: Unknown Etymology: Psacalium is of uncertain origin, while decompositum means divided more than once, usually many times. Synonyms: Cacalia decomposita, Mesadenia decomposita, Odontotrichum decompositum Editor: LCrumbacher 2011