Annuals; not scapose; (glaucous), glabrous or pubescent. Stems erect, unbranched or branched distally. Leaves basal and cauline; petiolate or sessile; basal (often withered by anthesis or fruiting), not or, rarely, rosulate, shortly petiolate, blade margins subentire, dentate, pinnatifid, or pinnatisect [rarely entire]; cauline sessile, blade (base usually auriculate), margins entire, dentate, or pinnatifid to pinnatisect. Racemes (corymbose, several-flowered), considerably elongated in fruit. Fruiting pedicels often recurved, sometimes divaricate-ascending, slender. Flowers: sepals ascending, oblong to ovate, lateral pair not saccate basally; petals white to purplish, spatulate to oblong, (subequaling or longer than sepals), claw not differentiated from blade; stamens slightly tetradynamous; filaments slightly dilated basally; anthers ovate; nectary glands each side of lateral stamen or semi-annular, median glands absent. Fruits (pendulous), sessile, cymbiform, orbicular, obovate [ovate, elliptic], smooth, strongly latiseptate; valves each with prominent midvein, glabrous or pubescent; replum entire or crenate, often perforated, (winged, wing flattened, with radiating rays); septum obsolete; ovule 1 per ovary; style distinct (relatively short) or obsolete; stigma entire. Seeds aseriate, flattened, not winged, elliptical to orbicular; seed coat not mucilaginous when wetted; cotyledons accumbent.

Distribution

w North America, nw Mexico.

Discussion

Species 5 (4 in the flora).

Thysanocarpus erectus S. Watson occurs in northwestern Mexico on Cedros and Guadalupe islands and on the mainland of Baja California.

Selected References

None.

Lower Taxa

Thysanocarpus conchuliferus, Thysanocarpus curvipes, Thysanocarpus laciniatus, Thysanocarpus radians

Key

1	Fruits cymbiform, wings strongly incurved (toward flat side of fruit); raceme internodes ca. 0.7-1.5(-2) mm in fruit.	Thysanocarpus conchuliferus
1	Fruits flat or plano-convex, wings not strongly incurved; raceme internodes (1.5-)2-18 mm in fruit	> 2
2	Fruiting pedicels weakly ascending, straight or nearly so (geniculately reflexed apically), 7-18 mm; fruits 7-10 mm wide, wings with distinct rays ± 0.1 mm wide.	Thysanocarpus radians
2	Fruiting pedicels smoothly recurved or straight and stiffly spreading, 2-7(-12) mm; fruits 2.5-6(-9) mm wide, wings with indistinct rays or (0-)0.2-0.5 mm wide	> 3
3	Cauline leaf blades lanceolate, widest at base, bases auriculate-clasping, auricles extending around stems (at least some leaves); basal leaf blade margins subentire to sinuate-dentate, never pinnatifid, surfaces often hirsute, sometimes glabrous.	Thysanocarpus curvipes
3	Cauline leaf blades linear to narrowly elliptic, widest near middle or equally wide throughout, bases not auriculate or inconspicuous auricles not extending around stems; basal leaf blade margins pinnatifid, sinuate-dentate, or subentire, surfaces usually glabrous, rarely sparsely hirsute.	Thysanocarpus laciniatus