glabrous, annual herbs. Leaves alternate, obovate-elliptic, toothed.
Inflorescence of capitula, heterogamous, minute, disciform, yellow, sessile or
with very short peduncles, in globose clusters on branches of dichotomous
cymes, involucre hemispheric. Bracts 2-seriate, broad, oblong, obtuse-subacute,
receptacle flat or slightly convex, naked. Outer florets female, many-seriate,
fertile. Disc-florets few, hermaphrodite, with sterile cypsela. Petals of
female florets absent or connate in very short, tubular corolla, that of
hermaphrodite florets with very short tube, regular, narrowly campanulate with
4-fid limb. Anther base obtuse, entire. Style of hermaphrodite florets with
short, flattened subacute arms, papillose on the back, that of female florets
with linear, obtuse arms. Fruit a cypsela, cypsela of female florets small,
hardly ribbed or costae, that of hermaphrodite florets abortive, pappus hairs
about 10, 1-seriate, dilated.