Draba alpina |
Draba murrayi |
|
---|---|---|
alpine Draba |
kathul mountain Draba |
|
Habit | Perennials; (cespitose); caudex branched (covered with persistent leaves or leaf remains); scapose. | Perennials; (cespitose); caudex often branched (covered with persistent leaves or leaf remains, branches sometimes terminating in sterile rosettes); 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, (0.4–)0.9–2.7(–3.5) dm, pubescent proximally, glabrous distally, trichomes simple, 0.2–1 mm, and often smaller, fewer short-stalked, 2–4-rayed ones. |
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 (0–0.7 cm), margin ciliate; blade oblanceolate to obovate, (0.3–)0.6–2.1(–2.8) cm × (1.5–)2.5–5(–9) mm, margins entire or sparsely denticulate, (ciliate, trichomes simple, 0.2–1.1 mm), surfaces pubescent with stalked, cruciform, and 2- or 3-rayed trichomes, (rays sometimes spurred), 0.1–0.6 mm, sometimes mostly simple trichomes adaxially. |
Cauline leaves | 0. |
1–6; sessile; blade ovate or oblong to lanceolate, margins usually entire, rarely sparsely denticulate, surfaces pubescent as basal. |
Racemes | 6–18-flowered, ebracteate, considerably elongated in fruit; rachis not flexuous, pubescent as stem. |
7–25-flowered, ebracteate, 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 ovate, 1.5–2.2 mm, pubescent, (trichomes simple and short-stalked, 2-rayed); petals white, obovate, 4–6 × 1.5–2.5 mm; anthers ovate, 0.4–0.5 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, usually straight, rarely curved, (4–)7–18 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). |
linear-lanceolate to narrowly elliptic, plane, flattened, 5–13 × 1.5–2 mm; valves glabrous; ovules 20–30 per ovary; style 0.6–1.5 mm. |
Seeds | (pale brown), ovoid, 0.9–1.3 × 0.6–0.9 mm. |
oblong, 0.9–1.2 × ca. 0.5 mm. |
2n | = 80. |
= 48. |
Draba alpina |
Draba murrayi |
|
Phenology | Flowering Jun–Aug. | Flowering Jun–Jul. |
Habitat | Moist tundra and ridges, sand and gravel flats or beaches | Rock outcrops and talus, open forests, dry slopes, alluvial gravels |
Elevation | 0-1000 m (0-3300 ft) | 150-900 m (500-3000 ft) |
Distribution |
LB; MB; NU; ON; QC; Greenland; Europe (Finland, Norway, Russia, Sweden)
|
AK; YT |
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.) |
Of conservation concern. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 7, p. 290. | FNA vol. 7, p. 321. |
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) | G. A. Mulligan: Canad. J. Bot. 57: 1874. (1979) |
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