3. Hesperidanthus barnebyi (S. L. Welsh & N. D. Atwood) Al-Shehbaz, Harvard Pap. Bot. 10: 50. 2005.
Thelypodiopsis barnebyi S. L. Welsh & N. D. Atwood, Brittonia 33: 300, fig. 6. 1981; Schoenocrambe barnebyi (S. L. Welsh & N. D. Atwood) Rollins
Perennials. Stems few to several from caudex, erect, 1-3.5 (-3.8) dm. Leaves subsessile or petiolate, (0.4-1 cm); blade oblong or elliptic to oblanceolate, 1.5-5 cm × 4-24 mm, base cuneate, margins entire or obscurely denticulate, apex obtuse to rounded. Racemes usually 2-8-flowered (rarely more). Fruiting pedicels ascending to divaricate, straight, 10-27 mm. Flowers: sepals green to purple, 5-8 × 2-3 mm; petals white or lilac (with darker purple veins), 9.5-12 × 2.5-3.5 mm, claw distinctly differentiated from blade, (narrower); filaments 2.5-3 mm; anthers linear, 2.5-3 mm; gynophore 0-1.5 mm. Fruits straight or curved, terete, 3.5-5.5 cm × 1-2 mm; ovules 24-42 per ovary; style subclavate, 1-2 mm; stigma flat, obscurely 2-lobed. Seeds 1.8-2.2 × 0.9-1.2 mm.
Flowering Apr-Jun. Mixed desert communities; of conservation concern; 1700-2000 m; Utah.
The species is restricted to the Chinle Formation in Emery and Wayne counties.
Hesperidanthus barnebyi, as Schoenocrambe barnebyi, is in the Center for Plant Conservation’s National Collection of Endangered Plants.