Fl. Bor.-Amer. 1: 335, plate 118. 1834.

Etymology: Greek krokis, downy fibers of woolen cloth, and - idium, diminutive, alluding to axillary tomentum
Treatment appears in FNA Volume 20. Treatment on page 641. Mentioned on page 541.

Annuals, (2–)4–12(–30) cm (usually glabrous but for axillary tomentum). Stems usually 1, erect, simple or branched near bases. Leaves (± fleshy) basal and cauline; alternate; petiolate (basal) or sessile; blades palmately nerved, spatulate or oblanceolate (basal) to lanceolate or linear, margins toothed or entire, faces glabrous or glabrate. Heads radiate, borne singly. Calyculi 0. Involucres ± hemispheric, 3–6+ mm diam. Phyllaries (veiny, often purple-tipped, each subtending a ray floret) persistent, 5–13+ in 1(–2) series, erect (reflexed in fruit), basally connate, elliptic to ovate, subequal, margins herbaceous to membranous. Receptacles dome-shaped to conic (heights equaling or greater than diameters), smooth, epaleate. Ray florets 5–13+, pistillate and fertile or neuter; corollas yellow (laminae conspicuous). Disc florets 12–60(–120+), bisexual, fertile; corollas yellow, tubes ± cylindric, longer than or equaling campanulate to cylindric throats, lobes 5, erect to spreading, deltate to lanceolate; style branches stigmatic in 2 lines, apices truncate-penicillate. Cypselae (stramineous to reddish brown) ± ellipsoid to fusiform, 5(–6)-nerved, ± papillate-hairy between nerves (papillae mucilaginous when wetted); pappi fragile or readily falling, usually of 20–40, white, barbellulate bristles (in 1 series), sometimes 0 on ray cypselae. x = 9.


w North America.


Species 1.

Selected References