Draba alpina |
Draba malpighiacea |
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alpine Draba |
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Habit | Perennials; (cespitose); caudex branched (covered with persistent leaves or leaf remains); scapose. | Perennials; caudex simple or branched (sometimes with persistent leaf bases); 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. |
unbranched, 0.5–1.5 dm, pubescent throughout, trichomes malpighiaceous, 0.2–0.5 mm, and sometimes simple. |
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. |
rosulate; petiolate; petiole not ciliate; blade oblanceolate to spatulate, 0.5–1.8 cm × 2–4 mm, margins entire or dentate, (not ciliate proximally), surfaces pubescent with malpighiaceous trichomes, 0.3–0.6 mm. |
Cauline leaves | 0. |
4–13; sessile; blade broadly ovate to lanceolate, margins denticulate, surfaces pubescent as basal. |
Racemes | 6–18-flowered, ebracteate, considerably elongated in fruit; rachis not flexuous, pubescent as stem. |
10–33-flowered, ebracteate, elongated in fruit; rachis not flexuous, glabrous or pubescent, trichomes simple and/or malpighiaceous. |
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. |
sepals ovate, 2.5–3 mm, subapically pubescent, (trichomes simple and malpighiaceous); petals yellow, oblanceolate, 4–5 × 1.5–2 mm; anthers oblong, 0.7–1 mm. |
Fruiting pedicels | ascending to divaricate-ascending, straight or, sometimes, slightly curved upwards, 4–14(–30) mm, pubescent, trichomes simple and 2–4-rayed. |
divaricate-ascending, straight or curved upward, 6–13 mm, pubescent abaxially, trichomes simple and/or malpighiaceous. |
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). |
elliptic to elliptic-lanceolate, plane, flattened, 5–10 × 1.5–2.2 mm; valves glabrous; ovules 14–18 per ovary; style 0.8–1.2 mm. |
Seeds | (pale brown), ovoid, 0.9–1.3 × 0.6–0.9 mm. |
ovoid, 1–1.4 × 0.7–0.9 mm. |
2n | = 80. |
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Draba alpina |
Draba malpighiacea |
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Phenology | Flowering Jun–Aug. | Flowering Jun–Aug. |
Habitat | Moist tundra and ridges, sand and gravel flats or beaches | Rock outcrops and rocky slopes in subalpine conifer forests |
Elevation | 0-1000 m (0-3300 ft) | 3000-3500 m (9800-11500 ft) |
Distribution |
LB; MB; NU; ON; QC; Greenland; Europe (Finland, Norway, Russia, Sweden)
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CO |
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.) |
Draba malpighiacea, which is restricted to higher elevations in Hinsdale, La Plata, and Montezuma counties, has been included within D. spectabilis by previous authors. Preliminary data suggest that it is one of the diploid parents of tetraploid D. spectabilis. It is readily distinguished from all species of Draba in Canada and the United States by having a leaf indumentum of exclusively malpighiaceous trichomes. The only other species in the flora area with such trichomes is D. sibirica, a stoloniferous, scapose perennial known only from Greenland. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 7, p. 290. | FNA vol. 7, p. 318. |
Parent taxa | Brassicaceae > tribe Arabideae > Draba | Brassicaceae > tribe Arabideae > Draba |
Sibling taxa | ||
Synonyms | D. alpina var. hydeana, D. alpina var. inflatisiliqua | |
Name authority | Linnaeus: Sp. Pl. 2: 642. (1753) | Windham & Al-Shehbaz: Harvard Pap. Bot. 12: 417. (2007) |
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