5. Streptanthus brachiatus F. W. Hoffman, Madroño 11: 230. 1952. TYPE: United Sates, California, Sonoma Co., serpentine ridge near Contact Mine, E of Pine Flat, 300 ft, 5 Jun 1949, A.rthur R. Kruckeberg & Freed W. Hoffman 2905 (holotype, UC!; isotypes, 2GH!, MO!, NY!, UC!).
Streptanthus brachiatus subsp. hoffmanii R. Dolan & LaPré, Madroño 36: 36. 1989. TYPE: United States, California, Lake Co., near Sonoma Co. line on Bear Ridge rd, ¼ mi. S of three-way jct. with Ridge Rd and Davies Rd, 2 May 1985, Lawrence LaPré s.n. (holotype, UC!; isotypes, CAS!, RSA!, UC!).
Herbs, biennial, glabrous throughout, somewhat glaucous. Stems 1.4–5(–6) dm, branched about base or rarely simple. Basal leaves rosulate, soon withered, shortly petiolate, broadly obovate to suborbicular, 1.5–4 cm, coarsely dentate, fleshy, mottled; middle cauline leaves ovate to cordate, 0.7–3.7 x 0.3–1.5 cm, sessile, auriculate to amplexicaul, serrate-dentate to entire; upper leaves similar, reduced. Racemes ebracteate, sometimes secund, lax, without a terminal cluster of sterile flowers; fruiting pedicels divaricate-ascending, straight, 1–2 mm. Flowers: sepals forming urceolate calyx, rose-purple to yellowish at base, ovate, 5–7 mm, keeled, erect, apex recurved; petals whitish, 7–10 mm, adaxial pair faintly purple-veined, abaxial pair with a purple spot; blade 1.5–3 x 1–1.5 mm, not crisped; claw 5–7 mm, as wide as or wider than blade; staminal filaments in 3 pairs of unequal length; adaxial pair completely united, usually recurved, 8–10 mm; abaxial pair united below middle, 4–7 mm; lateral pair 2–4 mm; anthers of adaxial stamens sterile, 0.7–1.2 mm; anthers of abaxial and lateral stamens fertile, 2–2.5 mm. Fruits 4–6 cm x 1–1.3 mm, divaricate-ascending, flattened, nearly straight, torulose; valves glabrous, with obscure midvein; gynophore 0.3–0.7 mm; replum constricted between seeds; style 0.1–0.4 mm; stigma subentire; ovules and seeds 22–30 per fruit. Seeds oblong, 1.8–2.5 x 0.7–0.9 mm; wing distal, ca. 0.1 mm wide, or absent. 2n = 28.
Habitat: serpentine barrens in chaparral, pine-oak or cypress woodland openings.
Elevation: 600–950 m.
Distribution: United States (California/Lake and Sonoma counties).