Chaetadelpha
Amer. Naturalist 7: 301. 1873.
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.