Draba breweri

S. Watson

Proc. Amer. Acad. Arts 23: 260. 1888.

Endemic
Synonyms: Draba breweri var. sublaxa Jepson
Treatment appears in FNA Volume 7. Treatment on page 297. Mentioned on page 277, 283, 298, 299.
Revision as of 23:56, 27 May 2020 by imported>Volume Importer

Perennials; (cespitose, grayish pubescent); caudex branched (sometimes covered with persistent leaf bases, branches short, compact); sometimes scapose. Stems unbranched, (0.1–)0.2–1(–1.5) dm, pubescent throughout, trichomes stalked, 4–10-rayed, 0.1–0.3 mm. Basal leaves rosulate; petiolate; petiole base ciliate, margin not ciliate, (trichomes simple and 2-rayed, 0.3–0.8 mm); blade oblanceolate to obovate, (0.3–)0.4–1.5(–2.5) cm × 1.5–3(–5) mm, margins usually entire, rarely dentate, surfaces densely pubescent with stalked, 4–10-rayed, stellate trichomes, 0.1–0.2 mm (sometimes 1 or more rays spurred). Cauline leaves 0–3(–6); sessile; blade oblong or lanceolate to ovate, margins entire (sometimes ciliate at base), surfaces usually pubescent as basal. Racemes (5–)7–18(–24)-flowered, ebracteate, slightly to considerably elongated in fruit; rachis not flexuous, pubescent with stalked, 4–10-rayed trichomes, (0.1–0.3 mm). Fruiting pedicels ascending, (sometimes slightly appressed to rachis), straight, 1.5–3(–4) mm, pubescent as rachis. Flowers: sepals (persistent), ovate, 1.2–2 mm, pubescent, (trichomes short-stalked, 2–6-rayed); petals white, spatulate to oblanceolate, 2–3 × 0.7–1.1 mm; anthers ovate, 0.2–0.25 mm. Fruits lanceolate or oblong to linear, usually slightly to strongly twisted, rarely plane, flattened, 3.5–9(–11) × 1.5–2.5 mm; valves pubescent, trichomes short-stalked, 2–5-rayed, 0.05–0.25 mm; ovules 28–40 per ovary; style 0.1–0.3(–0.4) mm. Seeds ovoid, 0.5–0.7 × 0.3–0.5 mm. 2n = 32.


Phenology: Flowering Jul–Aug.
Habitat: Rock outcrops, talus, exposed ridges, alpine areas
Elevation: 3100-4100 m

Discussion

The circumscription of Draba breweri was expanded by R. C. Rollins (1993) to include D. cana. Plants of D. cana differ from those of D. breweri by being non-cespitose (versus cespitose) and taller [(4–)10–30(–38) versus (1–)2–9(–15) cm], and by having basally bracteate (versus ebracteate) racemes, and stems, pedicels, and sepals pubescent with a mixture of simple and branched (versus exclusively branched) trichomes. Draba breweri is known to us from Alpine, Fresno, Inyo, Mono, Plumas, Tulare, and Tuolumne counties.

Selected References

None.

Lower Taxa

None.