26. Streptanthus morrisonii F. W. Hoffman, Madroño 11: 225. 1952. TYPE: United States, California, Sonoma Co., serpentine outcrop, headwaters of Big Austin Creek at Layton Chromite Mine, 26 Sep 1946, Freed W. Hoffman 1020 (holotype, UC!).

S. morrisonii subsp. elatus F. W. Hoffman, TYPE: United States, California, Napa-Lake Co. line, serpentine outcrop on low saddle ¼ mi W of White’s Point, Table Mt. rd., ca. 5 mi. E of Mountain Mill House, 3 May 1947, Arthur R. Kruckeberg 1438 (UC!).

S. morrisonii subsp. hirtiflorus F. W. Hoffman, TYPE: United States, California, Sonoma Co., headwaters of East Austin Creek, a short distance above Dorr’s Cabin, 16 Jun 1948, Freed W. Hoffman 2344 (holotype, UC!; isotypes, 2GH!, NY!).

S. morrisonii subsp. kruckebergii R. Dolan & LaPré, Madroño 36: 39. 1989. TYPE: United States, California, Lake Co., Dunnigan Hill in Knoxville Recreation Area, T11N, R5W, Sec. 11, 8 Jun 1985, Lawrence LaPré s.n. (holotype, UC!; isotypes, CAS!, RSA!, UC!).

     Herbs, biennial, glaucous, glabrous throughout except sometimes for sepals. Stems (2.5–)6.5–12(–15) dm, simple, often paniculately branched above. Basal leaves rosulate, fleshy, gray-green, often mottled above and purplish abaxially, petiolate, oblanceolate to broadly obovate or orbicular, 1–7 cm, dentate or repand; middle cauline leaves broadly ovate to narrowly lanceolate, 0.7–5 x 0.2–4 cm, sessile, auriculate to amplexicaul, entire; upper leaves much smaller. Racemes ebracteate, lax, secund, without a terminal cluster of sterile flowers; fruiting pedicels divaricate to ascending, straight 1–3(–4) mm. Flowers: sepals forming suburceolate calyx, pale yellow to violet, ovate-lanceolate, 5–8 mm, keeled, glabrous or sparsely to densely hirsute with trichomes to 1.3 mm, usually recurved at apex; petals barely exserted, creamy white with brownish purple veins, 7–10 mm; blade 2–3 x 1–2 mm, channeled, not crisped; claw 5–7 mm, about as wide as blade; filaments in 3 pairs of unequal length; adaxial pair united to apex, 7–9 mm; abaxial pair united along proximal half, 4–6 mm; lateral pair 2–4 mm; anthers of adaxial stamens sterile, 0.6–1 mm; anthers of abaxial and lateral stamens fertile, 2–3 mm. Fruits 2.5–8 cm x 1.5–2 mm, suberect to divaricate, straight or sometimes slightly curved, flattened, strongly torulose; valves glabrous, with a distinct midvein; gynophore 0.1–1 mm; replum constricted between seeds; style 0.1–0.2 mm; stigma entire; ovules and seeds 24–38 per fruit. Seeds oblong, 1.5–2 x 0.9–1.3 mm; wing absent or distal, 0.05–0.1 mm wide. 2n = 28.

Flowering: May–Sep.

Habitat: ridges, serpentine barrens and openings in serpentine chaparral, cypress-knob cone pine woodlands.

Elevation: 150–1100 m.

Distribution: United States (California).