Chaetadelpha

A. Gray ex S. Watson

Amer. Naturalist 7: 301. 1873.

Etymology: Greek chaite, long hair, bristles, and adelphe, sister, alluding to adnation of awns and bristles of pappi
Treatment appears in FNA Volume 19. Treatment on page 368. Mentioned on page 218.

Perennials, 15–40 cm; rhizomes stout, branching. Stems 2–4, ascending to suberect, freely branched, glabrous. Leaves basal and cauline (basal withered at flowering); sessile; blades linear to linear-lanceolate, margins entire; distal reduced to scales. Heads borne singly (terminal at ends of stems and branches). Peduncles not inflated, not bracteate. Calyculi of 4–5, minute bractlets. Involucres cylindric, 3–4 mm diam. Phyllaries 5 in 1 series, linear, equal, margins hyaline, apices acute. Receptacles flat, glabrous, epaleate. Florets 5; corollas pale lavender to white. Cypselae light tan, columnar, 5 ridge-angled, faces smooth, without grooves or striations, glabrous; pappi persistent (borne on minute, raised pedestals 0.1 mm), of 5, barbellate awns plus 35–50+, barbellulate bristles in 1–2 series, all ± connate basally (bristles ± in groups alternating with the awns). x = 9.

Distribution

sw United States.

Discussion

Species 1.