Athysanus unilateralis

(M. E. Jones) Jepson

Fl. W. Calif., 224. 1901

Basionyms: Draba unilateralis M. E. Jones Bull. Torrey Bot. Club 9: 124. 1882
Synonyms: Heterodraba unilateralis (M. E. Jones) Greene
Treatment appears in FNA Volume 7. Treatment on page 268. Mentioned on page 267.
Plants pubescent. Stems (0.3–)0.7–2.5(–3.5) dm. Basal leaves subsessile or petiole to 0.3 cm; blade oblanceolate, obovate, or oblong, (0.3–)0.7–2(–2.2) cm × (2–)4–7 mm, margins entire or with a tooth on each side, apex obtuse, surfaces uniformly pubescent, trichomes cruciform with fewer, 3-rayed ones. Cauline leaves 2–5; blade similar to but smaller than basal, (base cuneate, not auriculate). Fruiting pedicels stout, 1–2(–3) mm. Flowers: sepals 0.6–1 × 0.4–0.6 mm; petals spatulate, 1.3–1.7 × 0.5–0.8 mm; filaments 0.5–0.9 mm; anthers 0.1–0.2 mm. Fruits elliptic, obovate, or orbicular, flattened or slightly twisted; valves thickened, veins often prominent, glabrous or uniformly pubescent, trichomes subsessile or short-stalked, cruciform and 3-rayed, sometimes mixed with stouter, simple or forked, subsetiform ones to 0.6 mm, not hooked; septum complete, (membranous); ovules 6–12 per ovary; style 0.1–0.2 mm. Seeds often 2 or more, 0.9–1.2 × 0.6–0.8 mm.

Phenology: Flowering Feb–May.
Habitat: Open grassy slopes and flats, friable clay, flood plains, adobe and heavy gumbo clay, gypsum clay slopes
Elevation: 100-900 m


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Calif., Oreg., Mexico (Baja California).


It appears that Athysanus unilateralis is known in Oregon only from Jackson County; it is more widespread in California.



Lower Taxa

No lower taxa listed.