Helminthotheca

Annuals or biennials, 10-100+ cm; taprooted. Stems usually 1, erect, branched distally or throughout, hirsute to hispid or setose (hair tips 2-4-hooked). Leaves basal and cauline; basal ± petiolate, distal sessile; blades elliptic, lanceolate, oblanceolate, oblong, or ovate, margins usually dentate to pinnately lobed (faces hirsute to hispid, hair tips 2-4-hooked). Heads borne singly or in loose, corymbiform arrays. Peduncles (terminal and axillary) not inflated distally, seldom bracteate. Calyculi of (3-)5, cordate or ovate to lance-ovate, foliaceous bracts. Involucres ovoid to urceolate, 9-12+ mm diam. (larger in fruit). Phyllaries (5-)8-13+ in 1 series, lance-linear to linear, subequal, margins little, if at all, scarious, apices acuminate. Receptacles flat, pitted, glabrous, epaleate. Florets 30-60+; corollas yellow (often reddish abaxially). Cypselae (dimorphic): outer whitish, bodies gibbous, ribs 5-10, beaks about equaling bodies, fragile, faces hirtellous to pilosulous adaxially; inner reddish brown, bodies ± compressed-ellipsoid to fusiform, beaks about equaling or longer than bodies, fragile, faces transversely rugulose to muricate, otherwise glabrous; pappi persistent, of 10-15+, whitish, subequal, barbellate or plumose, subulate to setiform (basally connate) scales in 1-2 series. x = 5.