Tropidocarpum

Annuals; not scapose; pubescent or glabrous, trichomes simple, these mixed with smaller, short-stalked, Y-shaped, forked ones, rarely rays branched. Stems (usually several from base, rarely simple), usually ascending, decumbent, or prostrate, rarely erect, unbranched or branched [basally] distally, (slender). Leaves basal and cauline; petiolate or sessile; basal (withered by fruiting), not rosulate, petiolate, blade margins pinnatifid or pinnatisect; cauline sessile or subsessile, blade margins pinnatifid. Racemes (several-flowered, bracteate throughout), considerably elongated in fruit. Fruiting pedicels erect, ascending, or divaricate, slender. Flowers: sepals erect to ascending, oblong, (glabrous or pubescent); petals yellow, sometimes with purple tinge, oblanceolate, obovate, or spatulate, (slightly longer than sepals), claw undifferentiated from blade; stamens slightly tetradynamous; filaments sometimes slightly dilated basally; anthers ovate, (apex obtuse); nectar glands confluent, subtending bases of stamens. Fruits siliques or silicles, sessile, linear, oblong, or obdeltoid, smooth, strongly angustiseptate; valves [(2 or) 4 in T. capparideum, keeled], not veined, (thin-leathery throughout, or distally subwoody or thick-leathery and tuberculate-rugose), pubescent; replum rounded; septum complete or absent; ovules 4-70 per ovary; style distinct, (slender); stigma capitate. Seeds uniseriate or (in 4-valved fruits) 4-seriate, not winged, oblong; seed coat (reticulate), mucilaginous when wetted; cotyledons incumbent. x = 8.