R. M. King & H. Robinson

Phytologia 24: 66. 1972.

Etymology: Asa, honoring American botanist Asa Gray, 1810–1888, and Greek anthos, flower
Treatment appears in FNA Volume 21. Treatment on page 509. Mentioned on page 460, 507.

Perennials or subshrubs, 30–60(–100) cm. Stems erect, much branched. Leaves cauline; mostly opposite (distal sometimes alternate); ± sessile [petiolate]; blades 1-nerved (or nerves parallel, mostly linear to filiform [lanceolate] (distal usually filiform to scalelike), canescent, often with axillary, ± 4-ranked, canescent, fascicles of scale-leaves), margins entire, faces glabrous or puberulent, usually gland-dotted. Heads discoid, in narrow, racemiform [corymbiform to paniculiform] arrays. Involucres ± obconic, 4–5 mm diam. Phyllaries persistent, 20–25 in 4–8 series, not notably nerved, lance-ovate to oblong, unequal (herbaceous to scarious, becoming indurate). Receptacles flat, epaleate. Florets 8–14; corollas whitish, throats narrowly cylindric (lengths 6–8 times diams.); styles: bases not enlarged, glabrous, branches narrowly clavate (distally dilated, not notably papillose). Cypselae narrowly prismatic, (9–)10-ribbed, scabrellous on ribs; pappi persistent, of 20–100 barbellate (at least distally) bristles in 1–3 series.


sw United States, w Mexico.


Species 3 (1 in the flora).

Asanthus has been included within Steviopsis (see discussion under 404. Brickelliastrum).

Selected References