Draba alpina |
Draba daviesiae |
|
---|---|---|
alpine Draba |
bitter root Draba |
|
Habit | Perennials; (cespitose); caudex branched (covered with persistent leaves or leaf remains); scapose. | Perennials; (densely pulvinate); caudex branched (branches elongated, loose, with persistent leaf remains, terminating in flowering or sterile shoots); 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, (0.05–)0.2–0.6 dm, glabrous. |
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. |
(densely imbricate); rosulate; petiolate; petiole ciliate throughout; blade (fleshy), oblong to obovate or oblanceolate, 0.3–0.7(–1) cm × 1–2(–2.5) mm, margins entire, (ciliate, trichomes simple, 0.1–0.5 mm, apex obtuse), surfaces glabrous (midvein obscure abaxially). |
Cauline leaves | 0. |
0. |
Racemes | 6–18-flowered, ebracteate, considerably elongated in fruit; rachis not flexuous, pubescent as stem. |
2–8(–10)-flowered, ebracteate, (subcorymbose), slightly elongated in fruit; rachis not flexuous, glabrous. |
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 oblong, 1.5–2.2 mm, glabrous; petals pale to bright yellow, spatulate, 3.5–4 × 1–2 mm; anthers ovate, 0.3–0.4 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 (not decurrent basally), straight, 4–10 mm, glabrous. |
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). |
ovate to oblong-elliptic, plane, flattened, 4–8 × 2–4 mm; valves (obscurely veined), glabrous; ovules 6–14 per ovary; style 0.1–0.5 mm. |
Seeds | (pale brown), ovoid, 0.9–1.3 × 0.6–0.9 mm. |
ovoid, 1.2–1.5 × 0.8–1 mm. |
2n | = 80. |
|
Draba alpina |
Draba daviesiae |
|
Phenology | Flowering Jun–Aug. | Flowering Jul–Aug. |
Habitat | Moist tundra and ridges, sand and gravel flats or beaches | Talus slopes, rock crevices and cracks, rocky ridges and slides, alpine meadows |
Elevation | 0-1000 m (0-3300 ft) | 2700-2900 m (8900-9500 ft) |
Distribution |
LB; MB; NU; ON; QC; Greenland; Europe (Finland, Norway, Russia, Sweden)
|
MT |
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.) |
Although originally described as a variety of Draba apiculata (= D. globosa), D. daviesiae is distinct morphologically. It is easily distinguished from the former by its densely pulvinate habit, obtuse leaf blades, and obscurely veined fruit valves. By contrast, D. globosa exhibits a cespitose but non-pulvinate habit, acute leaf blades, and prominently veined fruit valves. Draba daviesiae is known from the Bitterroot Mountains in Ravalli County. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 7, p. 290. | FNA vol. 7, p. 305. |
Parent taxa | Brassicaceae > tribe Arabideae > Draba | Brassicaceae > tribe Arabideae > Draba |
Sibling taxa | ||
Synonyms | D. alpina var. hydeana, D. alpina var. inflatisiliqua | D. apiculata var. daviesiae, D. densifolia var. daviesiae |
Name authority | Linnaeus: Sp. Pl. 2: 642. (1753) | (C. L. Hitchcock) Rollins: Contr. Gray Herb. 214: 5. (1984) |
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