Draba graminea |
Draba ramosissima |
|
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Rocky Mountain Draba |
branch Draba |
|
Habit | Perennials; (cespitose); caudex simple or branched (with persistent leaf bases); not scapose. | Perennials; caudex branched (well-developed, 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. |
unbranched proximally, paniculately branched distally, 0.7–3.8(–5) dm, pubescent proximally, trichomes short-stalked, 2–4-rayed, 0.1–0.6 mm, sometimes with simple ones, 0.4–0.8 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. |
rosulate; petiolate; petiole (to 2 cm), ciliate (trichomes simple, 0.3–0.5 mm); blade oblanceolate, (0.7–)1–5.5 cm × 2–8 mm, margins dentate, surfaces pubescent with short-stalked to subsessile, 3- or 4-rayed trichomes, 0.1–0.5 mm, adaxially sometimes also simple, 0.4–1.3 mm. |
Cauline leaves | (1–)3–9(–12) (as bracts); sessile; blade linear to oblanceolate or lanceolate, margins entire, (ciliate proximally, similar to basal). |
(5–)7–15(–21); sessile; blade ovate to oblong or elliptic to lanceolate, margins usually coarsely dentate or serrate, rarely subpinnatifid, surfaces pubescent as basal. |
Racemes | 3–15-flowered, bracteate, elongated in fruit; rachis not flexuous, usually pubescent as stem, rarely glabrous. |
9–28-flowered, ebracteate, paniculate; rachis not flexuous, pubescent as stem. |
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. |
sepals oblong, 2.5–3 mm, pubescent, (trichomes simple and subsessile, 2–4-rayed); petals white, spatulate, 4–6 × 1.5–2.5 mm; anthers oblong, 0.5–0.6 mm. |
Fruiting pedicels | divaricate-ascending, usually straight, rarely curved upward, 3–10(–15) mm, usually pubescent as stem, rarely glabrous. |
horizontal to divaricate-ascending, straight, (4–)6–12(–15) mm, pubescent, trichomes 2–4-rayed. |
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. |
narrowly oblong to elliptic or oblong-lanceolate, often strongly twisted, flattened, 5–11 × 1.5–2.2 mm; valves pubescent, trichomes subsessile or sessile, 2–4-rayed, 0.07–0.3 mm; ovules 4–10(–12) per ovary; style (1)1.5–3(–4) mm, (sparsely pubescent). |
Seeds | ovoid, 1.2–1.5 × 0.7–1 mm. |
oblong, 1.2–1.8 × 0.6–0.9 mm. |
2n | = 18. |
= 16. |
Draba graminea |
Draba ramosissima |
|
Phenology | Flowering Jul–Sep. | Flowering Apr–Jun. |
Habitat | Rocky areas and ridges, alpine tundra, gravel bars in streams | Limestone cliffs and outcrops, shale barrens, rocky wooded areas |
Elevation | 3000-4100 m (9800-13500 ft) | 0-1100 m (0-3600 ft) |
Distribution |
CO
|
DC; KY; MD; NC; TN; VA; WV |
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. | FNA vol. 7, p. 332. |
Parent taxa | Brassicaceae > tribe Arabideae > Draba | Brassicaceae > tribe Arabideae > Draba |
Sibling taxa | ||
Synonyms | Braya graminea, D. chrysantha var. graminea, D. chrysantha var. hirticaulis | Alyssum dentatum, D. dentata, D. ramosissima var. glabrifolia |
Name authority | Greene: Pl. Baker. 3: 5. (1901) | Desvaux: J. Bot. Agric. 3: 186. (1815) |
Web links |