Caulanthus barnebyi

Perennials; glabrous throughout. Stems erect or ascending, unbranched or branched distally, 5-11 dm. Basal leaves not rosulate; petiole 1.5-3.8 cm; blade broadly obovate to broadly ovate or oblong, 3.5-15.5 cm × 22-100 mm, margins entire or coarsely dentate-sinuate. Cau-line leaves (distalmost) shortly petiolate to subsessile; blade linear to lanceolate or oblanceolate, margins entire. Racemes (densely flowered), without a terminal cluster of sterile flowers. Fruiting pedicels ascending, 5-17 mm. Flowers: sepals erect (purplish or sometimes green), ovate-oblong to lanceolate, 7.5-11 × 2.5-3 mm (equal); petals creamy white (with prominent purple or brown veins),12.5-18.5 mm, blade 6-8 × 2-2.5 mm, not or slightly crisped, claw oblanceolate, 5-9 × 1.2-2 mm; filaments tetradynamous, median pairs 3-5 mm, lateral pair 2.5-4.5 mm; anthers narrowly oblong, equal, 3-4.5 mm. Fruits divaricate to ascending (often distinctly curved), terete, 5.7-12.5 cm × 1.7-2.3 mm; valves each with obscure midvein; ovules 76-90 per ovary; style usually obsolete, rarely to 2.5 mm; stigma strongly 2-lobed (lobes to 0.4 mm, connivent, opposite replum). Seeds 1.4-2.1 × 0.8-1.2 mm. 2n = 20.

Flowering May-Jun. Dry, steep slopes, rocky outcrops, on slate, metamorphic, or igneous substrates; of conservation concern; 1300-1500 m; Nev.

Caulanthus barnebyi is known from Humboldt and Pershing counties.