Psacalium

Perennials, [10–]80–150[–300] cm (rhizomes usually fleshy; plants hairy or tufted-hairy to unevenly glabrate). Stems single or clustered, erect. Leaves basal and cauline (proximal largest, cauline progressively smaller distally, bractlike); alternate; petiolate (petioles well defined, attached to blades at bases [attached near centers, leaves peltate]); blades palmately or pinnately nerved (and, usually, lobed), mostly ovate to elliptic [orbiculate, polygonal], ultimate margins entire or toothed, faces glabrous or sparsely [densely] hairy. Heads discoid, in corymbiform to paniculiform arrays. Calyculi of 1–3[–5] bractlets (shorter than [equaling or longer than] phyllaries). Involucres cylindric to weakly turbinate, 1.5–4[–10+] mm diam. Phyllaries persistent, mostly 5–8[–17] in 1–2 series, erect, distinct, ovate, obovate, or oblong, subequal, margins scarious (tips greenish or gray to whitish, not black). Receptacles flat, foveolate (sometimes hairy), epaleate. Ray florets 0. Disc florets 5–8[–80], bisexual, fertile; corollas white or ochroleucous [yellow, purplish], tubes longer than the campanulate or ± lacking throats, lobes 5, ascending to spreading, lance-linear; style branches: stigmatic areas continuous, apices rounded-truncate. Cypselae mostly ± ellipsoid, ± compressed, [10–]14–18-ribbed, glabrous or hairy; pappi [0] persistent (fragile), of 100–120, white or creamy, barbellulate bristles. x = 30.

Distribution

sw United States, mostly Mexico and Central America.

Discussion

Species ca. 42 (1 in the flora).

Selected References

Robinson, H. and R. D. Brettell. 1973b. Studies in the Senecioneae (Asteraceae). III. The genus Psacalium. Phytologia 27: 254–264.

Lower Taxa

Psacalium decompositum