54. Tropidocarpum Hooker, Icon. Pl. 1: plate 43. 1836.
[Greek tropis, keel, and karpos, fruit, alluding to fruit shape]
Ihsan A. Al-Shehbaz
Agallis Philippi; Twisselmannia Al-Shehbaz
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.
Species 4 (3 in the flora): California, c Mexico, South America (c Chile).
SELECTED REFERENCES Al-Shehbaz, I. A. 2003c. A synopsis of Tropidocarpum (Brassicaceae). Novon 13: 392-395. Al-Shehbaz, I. A. and R. A. Price. 2001. The Chilean Agallis and Californian Tropidocarpum (Brassicaceae) are congeneric. Novon 11: 292-293. Robinson, B. L. 1896. The fruit of Tropidocarpum. Erythea 4: 108-119.