29. Streptanthus petiolaris A. Gray, Mem. Amer. Acad. Arts 4: 7. 1849; Arabis petiolaris (A. Gray) A. Gray, Proc. Amer. Acad. Arts 6: 187. 1863; Erysimum petiolare (A. Gray) Kuntze, Revis. Gen. Pl. 2: 933. 1891. TYPE: United States, Texas, San Marcos Springs, 1847, Charles Wright s.n. (holotype, GH!).

Streptanthus brazoensis Buckley, Proc. Acad. Nat. Sci. Philadelphia 448. 1891. TYPE: United States, Texas: Fort Belknap, on the upper Brazos, May 1861, S. B. Buckley s.n. (holotype, PH!).

     Herbs, annual, pilose on proximal half, glabrous distally. Stems 2–12 dm, simple or branched above. Basal leaves subrosulate, long petiolate, oblanceolate in outline, 3–21 cm, lyrate-pinnatifid, with dentate lobes, pilose; middle cauline leaves long petiolate, lyrate-pinnatifid or hastate, 2–14 x 0.5–7 cm; upper leaves linear lanceolate, petiolate, entire. Racemes ebracteate, lax, without a terminal cluster of sterile flowers; fruiting pedicels divaricate to ascending, straight or curved upwards, 7–13 mm. Flowers: sepals forming subcampanulate calyx, lavender, oblong, 3–4.5 mm, not keeled; petals white to lavender, 4–8 mm; blade 1.5–4 x 1.5–2 mm, not crisped; claw 2.5–4 mm, narrower than blade; stamens tetradynamous; median filament pairs free, 2.5–4 mm; lateral pair 1.5–3 mm; anthers of all stamens fertile, 0.5–1 mm. Fruits 4–9 cm x 3.5–5 mm, suberect to divaricate-ascending, strongly flattened, straight, slightly torulose; valves glabrous, with obscure midvein; gynophore 0.3–0.7 mm; replum straight; style 0.5–2.7 mm; stigmas slightly 2-lobed; ovules and seeds 28–50 per fruit. Seeds orbicular, 3.5–5 mm diam.; wings continuous, 0.8–1.4 mm wide. 2n = 28.

Flowering: Mar–May.

Habitat: thickets, roadsides, canyons, grassy grounds, bluffs, knolls, rocky limestone prairies, juniper-oak woods.

Distribution: United States (Texas).