Draba graminea |
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Rocky Mountain Draba |
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Habit | Perennials; (cespitose); caudex simple or branched (with persistent leaf bases); not scapose. |
Stems | unbranched, 0.1–0.5(–0.8) dm, usually pubescent throughout, rarely glabrous, trichomes simple or subsessile, 2-rayed or spurred, (crisped), 0.1–0.5 mm. |
Basal leaves | rosulate; petiolate; petiole ciliate, (trichomes usually straight and simple, rarely also 2-rayed, 0.2–0.6(–0.8) mm); blade linear to linear-oblanceolate, (0.5–)1–4 cm × 0.3–2(–3) mm, margins entire (pubescent as petiole), surfaces glabrous. |
Cauline leaves | (1–)3–9(–12) (as bracts); sessile; blade linear to oblanceolate or lanceolate, margins entire, (ciliate proximally, similar to basal). |
Racemes | 3–15-flowered, bracteate, elongated in fruit; rachis not flexuous, usually pubescent as stem, rarely glabrous. |
Flowers | sepals ovate, 1.5–2.5 mm, glabrous or pubescent, (trichomes simple and short-stalked, 2-rayed); petals yellow, spatulate to obovate, 3–5 × 1.5–3 mm; anthers ovate, 0.3–0.5 mm. |
Fruiting pedicels | divaricate-ascending, usually straight, rarely curved upward, 3–10(–15) mm, usually pubescent as stem, rarely glabrous. |
Fruits | ovate-elliptic to lanceolate, slightly twisted or plane, flattened, 5–11 × 2.5–5 mm; valves glabrous; ovules 8–16 per ovary; style 0.2–0.7 mm. |
Seeds | ovoid, 1.2–1.5 × 0.7–1 mm. |
2n | = 18. |
Draba graminea |
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Phenology | Flowering Jul–Sep. |
Habitat | Rocky areas and ridges, alpine tundra, gravel bars in streams |
Elevation | 3000-4100 m (9800-13500 ft) |
Distribution |
CO
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Discussion | Of conservation concern. Draba graminea is occasionally confused with D. crassa, which occupies similar habitats and elevations. It is easily distinguished from the latter by having narrower [0.3–2(–3) versus 2.5–8(–10) mm wide] basal leaves and bracteate (versus ebracteate) racemes. It is known to us only from Hinsdale, La Plata, Ouray, San Juan, and San Miguel counties. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 7, p. 309. |
Parent taxa | Brassicaceae > tribe Arabideae > Draba |
Sibling taxa | |
Synonyms | Braya graminea, D. chrysantha var. graminea, D. chrysantha var. hirticaulis |
Name authority | Greene: Pl. Baker. 3: 5. (1901) |
Web links |