Draba ventosa |
Draba aprica |
|
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wind river Draba, wind river whitlow-grass |
hairy Draba, openground Draba |
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Habit | Perennials; (cespitose); caudex branched (covered with persistent leaves, branches creeping, sometimes terminating in sterile rosettes); scapose. | Annuals; not scapose. |
Stems | unbranched, (0.1–)0.2–0.4(–0.6) dm, densely pubescent throughout, trichomes 2–6-rayed, 0.1–0.6 mm. |
usually branched distally, (0.3–)0.7–3(–3.6) dm, pubescent throughout, trichomes short-stalked to subsessile, cruciform, 0.1–0.5 mm. |
Basal leaves | (imbricate); rosulate; subsessile; petiole base and margin not ciliate; blade obovate to oblanceolate, (0.4–)0.5–1 cm × 1.5–4.5 mm, margins entire, surfaces densely pubescent with stalked, 2–6-rayed trichomes, (0.1–)0.2–0.9 mm. |
not rosulate; petiolate; petiole (to 1 cm), ciliate throughout; blade obovate to spatulate or ovate to suborbicular, 0.6–2.5 cm × 3–10 mm, margins usually entire, rarely toothed, surfaces pubescent with stalked, cruciform trichomes, 0.1–0.5 mm. |
Cauline leaves | 0. |
(5–)8–20(–25); sessile; blade oblong to lanceolate, margins entire, (not ciliate), surfaces pubescent as basal. |
Racemes | 5–10(–16)-flowered, ebracteate, slightly elongated in fruit; rachis not flexuous, densely pubescent as stem. |
7–46-flowered, ebracteate, elongated in fruit, (lateral racemes from axils of distalmost leaves subumbellate); rachis not flexuous, pubescent as stem. |
Flowers | sepals broadly ovate, 2–2.5 mm, pubescent, (trichomes short-stalked, 2–6-rayed); petals yellow, obovate, 3.5–5.5 × 1.5–3 mm; anthers oblong, 0.5–0.6 mm. |
(late ones cleistogamous, apetalous); sepals oblong, 0.6–1.2 mm, pubescent; petals white, spatulate, 1.3–2.5 × 0.5–1 mm; anthers ovate, 0.1–0.2(–0.05 in cleistogamous flowers) mm. |
Fruiting pedicels | horizontal to divaricate-ascending, straight or slightly curved upward, 2–7(–9) mm, densely pubescent, trichomes 2–6-rayed, (0.1–0.6 mm). |
horizontal to divaricate-ascending, straight, 2–5 mm, pubescent, trichomes subsessile, 4-rayed. |
Fruits | suborbicular to broadly ovate, plane, inflated basally, flattened distally, 4–7.5(–9) × 3.5–5 mm; valves densely pubescent, trichomes short-stalked, 2–6-rayed, 0.15–0.5 mm; ovules 8–12 per ovary; style (0.5–)0.7–1.4 mm. |
linear-ellipsoid to ellipsoid, plane, flattened, (3–)4–6 × 0.8–1.1 mm; valves pubescent, trichomes subsessile, (2–)4-rayed, 0.03–0.12 mm; ovules 4–6(–8) per ovary; style 0.07–0.13 mm. |
Seeds | oblong, 1.4–1.9 × 0.9–1.2 mm. |
ovoid, 0.9–1.1 × 0.5–0.6 mm. |
2n | = 36. |
|
Draba ventosa |
Draba aprica |
|
Phenology | Flowering Jul–Aug. | Flowering Mar–May. |
Habitat | Talus slopes and alpine tundra | Open knolls, rocky roadsides, rock outcrops, igneous glades, woods, alluvial areas near streams |
Elevation | 2000-4000 m (6600-13100 ft) | 100-400 m (300-1300 ft) |
Distribution |
CO; UT; WY; AB; BC; YT |
AR; GA; MO; OK; SC
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Discussion | G. A. Mulligan (1971b) first reported apomixis in Draba ventosa based on studies of Canadian populations. This has now been confirmed in one of the southernmost populations (Duchesne County, Utah; M. D. Windham, unpubl.) as well. The species is easily overlooked and the large geographic gap between the Canadian and United States populations is likely to be narrowed or eliminated by additional collecting in western Montana. The limits of this species were expanded by C. L. Hitchcock (1941) to include D. ruaxes, but there are clear differences between them that support their recognition as distinct species. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Source | FNA vol. 7, p. 344. | FNA vol. 7, p. 290. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | D. brachycarpa var. fastigiata | |
Name authority | A. Gray: Amer. Naturalist 8: 212. (1874) | Beadle: in J. K. Small, Fl. S.E. U.S. ed. 2, 1336, 1375. (1913) |
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