2. Athysanus unilateralis (M. E. Jones) Jepson, Fl. W. Calif., 224. 1901; Draba unilateralis M. E. Jones, Bull. Torrey Bot. Club 9: 124. 1882; Heterodraba unilateralis (M. E. Jones) Greene, Bull. Calif. Acad. Sci. 1: 72. 1885. TYPE: Mexico, [Baja California], Valley of Palms, 7 Apr 1882, Marcus E. Jones 3687 (holotype, POM; isotypes, NY!, 3US!).
Herbs, pubescent. Stems (0.3–)0.7–2.5(–3.5) dm. Basal leaves subsessile or with petioles to 3 mm, oblanceolate, obovate, or oblong, entire or with a tooth on each side, apex obtuse, (3–)7–20(–22) x (2–)4–7 mm, uniformly pubescent on both surfaces with cruciform and much fewer 3-rayed trichomes; cauline leaves 2–5, similar but smaller than basal ones, cuneate, not auriculate. Fruiting pedicels stout, 1–2(–3) mm. Sepals oblong, 0.6–1 x 0.4–0.6 mm; petals white, 1.3–1.7 x 0.5–0.8 mm; filaments 0.5–0.9 mm; anthers 0.1–0.2 mm; ovules 6–12 per ovary. Fruits elliptic, obovate, or orbicular, latiseptate, wingless, indehiscent or tardily dehiscent, flat or slightly twisted; valves thickened, often with prominent veins, glabrous or uniformly pubescent with subsessile or short-stalked cruciform and 3-rayed trichomes, these sometimes mixed with stouter and subsetose simple or forked, subsetose trichomes to 0.6 mm; septum complete, membranous; style 0.1–0.2 mm. Seeds often 2 or more, brown, 0.9–1.2 x 0.6–0.8 mm.
Habitat: open grassy slopes and flats, friable clay, flood plains, adobe and heavy gumbo clay, gypsum clay slopes.
Elevation: 100–900 m.
Distribution: Mexico (Baja California), United States (California, SW Oregon/Jackson Co.).