Draba alpina |
Draba aprica |
|
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alpine Draba |
hairy Draba, openground Draba |
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Habit | Perennials; (cespitose); caudex branched (covered with persistent leaves or leaf remains); scapose. | Annuals; not scapose. |
Stems | unbranched, (0.3–)0.5–1.7(–2.8) dm, pubescent throughout, trichomes simple and 2-rayed, 0.3–0.8 mm, with 3–5-rayed ones, 0.1–0.3 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 | rosulate; petiolate; petiole base (not thickened), ciliate, (trichomes simple, 0.3–1 mm); blade oblanceolate to obovate or lanceolate to oblong, 0.8–3(–4.5) cm × 2.5–6(–9) mm, margins entire, surfaces abaxially pubescent with stalked, 2–4-rayed trichomes, 0.1–0.5 mm, with simple ones (midvein obscure, not thickened), adaxially glabrous or sparsely pubescent with simple and stalked, 2–4-rayed trichomes. |
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 | 6–18-flowered, ebracteate, considerably elongated in fruit; rachis not flexuous, 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 (purplish tinged), narrowly ovate, 2.5–3 mm, pubescent, (trichomes simple and fewer, stalked, 2-rayed); petals bright yellow, narrowly obovate, 3.5–5 × 1.7–2.5 mm; anthers ovate, 0.3–0.4 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 | ascending to divaricate-ascending, straight or, sometimes, slightly curved upwards, 4–14(–30) mm, pubescent, trichomes simple and 2–4-rayed. |
horizontal to divaricate-ascending, straight, 2–5 mm, pubescent, trichomes subsessile, 4-rayed. |
Fruits | elliptic, plane, flattened, 6–10 × 2–3 mm; valves glabrous or glabrescent, trichomes simple, (not confined to replum); ovules 12–24 per ovary; style 0.2–0.3 mm (stigma about as wide as style). |
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 | (pale brown), ovoid, 0.9–1.3 × 0.6–0.9 mm. |
ovoid, 0.9–1.1 × 0.5–0.6 mm. |
2n | = 80. |
|
Draba alpina |
Draba aprica |
|
Phenology | Flowering Jun–Aug. | Flowering Mar–May. |
Habitat | Moist tundra and ridges, sand and gravel flats or beaches | Open knolls, rocky roadsides, rock outcrops, igneous glades, woods, alluvial areas near streams |
Elevation | 0-1000 m (0-3300 ft) | 100-400 m (300-1300 ft) |
Distribution |
LB; MB; NU; ON; QC; Greenland; Europe (Finland, Norway, Russia, Sweden)
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AR; GA; MO; OK; SC
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Discussion | The synonymy above includes two North American names overlooked by C. L. Hitchcock (1941) and R. C. Rollins (1993). Draba alpina was broadly delimited by O. E. Schulz (1927) and included 17 varieties, some of which (e.g., corymbosa, oxycarpa, pilosa) are recognized herein as distinct species. The name D. alpina was so misapplied that it was used for any circumpolar or alpine, scapose, yellow-flowered, perennial Draba. Various chromosome numbers (e.g., 2n = 64, 80, 112, 120; S. I. Warwick and I. A. Al-Shehbaz 2006) have been reported for the species. As circumscribed here, it has the narrow distribution outlined above and includes plants with 2n = 80. Reports of the species from Alaska, Canadian Northwest Territories and Yukon, Siberia, eastern Asia, Russian Far East, and the Central Asian republics are either suspect or very unlikely. The entire D. alpina complex (including the above three species, D. glacialis Adams, D. macounii, etc.) is in need of critical molecular, cytological, and morphological study. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Source | FNA vol. 7, p. 290. | FNA vol. 7, p. 290. |
Parent taxa | Brassicaceae > tribe Arabideae > Draba | Brassicaceae > tribe Arabideae > Draba |
Sibling taxa | ||
Synonyms | D. alpina var. hydeana, D. alpina var. inflatisiliqua | D. brachycarpa var. fastigiata |
Name authority | Linnaeus: Sp. Pl. 2: 642. (1753) | Beadle: in J. K. Small, Fl. S.E. U.S. ed. 2, 1336, 1375. (1913) |
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