Draba graminea |
Draba nemorosa |
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Rocky Mountain Draba |
woodland Draba, woodland whitlow-grass, woods Draba, woods whitlow-grass, yellow whitlow-grass |
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Habit | Perennials; (cespitose); caudex simple or branched (with persistent leaf bases); not scapose. | Annuals; 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 or branched proximally, (0.3–)0.6–4.5(–6) dm, densely pubescent proximally, glabrous distally, trichomes simple, 0.5–1.3 mm, and stalked, 2–4-rayed, 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. |
rosulate or not, petiolate; petiole ciliate throughout; blade oblong-obovate or oblanceolate, (0.4–)1–3.5(–5) cm × (2–)5–15(–20) mm, margins usually dentate to denticulate, rarely subentire, surfaces sparsely to densely pubescent with stalked, 2- or 3-rayed, and cruciform trichomes, 0.1–0.5 mm. |
Cauline leaves | (1–)3–9(–12) (as bracts); sessile; blade linear to oblanceolate or lanceolate, margins entire, (ciliate proximally, similar to basal). |
4–12(–15); sessile; blade broadly ovate to oblong, margins dentate or denticulate, surfaces pubescent, abaxially as basal, adaxially with primarily simple, and 2- or 3-rayed trichomes. |
Racemes | 3–15-flowered, bracteate, elongated in fruit; rachis not flexuous, usually pubescent as stem, rarely glabrous. |
(10–)18–60(–92)-flowered, ebracteate, considerably elongated in fruit; rachis not flexuous (straight), 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. |
sepals ovate, (0.7–)0.9–1.6 mm, sparsely pubescent, (trichomes simple); petals yellow, spatulate to oblanceolate, (1.2–)1.7–2.2(–2.5) × (0.4–)0.6–1 mm, (deeply notched); anthers broadly ovate to subreniform, 0.1–0.2 mm. |
Fruiting pedicels | divaricate-ascending, usually straight, rarely curved upward, 3–10(–15) mm, usually pubescent as stem, rarely glabrous. |
divaricate, straight, 7–28(–35) mm [(1.5–)2–7 times longer than fruit], 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. |
oblong to elliptic or, rarely, oblong-oblanceolate, plane, slightly flattened, (3–)5–8 (–10) × 1.5–2.5 mm; valves glabrous or puberulent, trichomes simple, antrorse, 0.05–0.2 mm; ovules (30–)36–60(–72) per ovary; style 0.01–0.1 mm. |
Seeds | ovoid, 1.2–1.5 × 0.7–1 mm. |
ovoid, 0.5–0.7(–0.8) × 0.3–0.4(–0.5) mm. |
2n | = 18. |
= 16. |
Draba graminea |
Draba nemorosa |
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Phenology | Flowering Jul–Sep. | Flowering Apr–Jul. |
Habitat | Rocky areas and ridges, alpine tundra, gravel bars in streams | Rock outcrops, open wooded slopes, meadows and prairies, stream banks, roadsides, disturbed gravelly grounds, waste places |
Elevation | 3000-4100 m (9800-13500 ft) | 0-2700 m (0-8900 ft) |
Distribution |
CO
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AK; CA; CO; IA; ID; MI; MN; MT; ND; NE; NV; OR; SD; UT; WA; WI; WY; AB; BC; MB; NT; NU; ON; QC; SK; YT; Europe; Asia [Introduced in North America; introduced also in Australia]
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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.) |
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Source | FNA vol. 7, p. 309. | FNA vol. 7, p. 321. |
Parent taxa | Brassicaceae > tribe Arabideae > Draba | Brassicaceae > tribe Arabideae > Draba |
Sibling taxa | ||
Synonyms | Braya graminea, D. chrysantha var. graminea, D. chrysantha var. hirticaulis | D. dictyota, D. nemoralis, D. nemorosa var. brevisilicula, D. nemorosa var. hebecarpa, D. nemorosa var. leiocarpa, Tomostima nemorosa |
Name authority | Greene: Pl. Baker. 3: 5. (1901) | Linnaeus: Sp. Pl. 2: 643. (1753) |
Web links |
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