Draba alpina |
Draba stenopetala |
|
---|---|---|
alpine Draba |
Anadyr Draba, star-flower Draba, star-flower whitlow-grass |
|
Habit | Perennials; (cespitose); caudex branched (covered with persistent leaves or leaf remains); scapose. | Perennials; (pulvinate); caudex branched (covered with persistent leaves, branches sometimes terminating in sterile rosettes); 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, (0.02–)0.07–0.2(–0.3) dm, pubescent throughout, trichomes simple and short-stalked, 2–5-rayed, 0.1–0.5 mm, (sometimes simple ones very sparse). |
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 base and margin ciliate, (trichomes simple and 2-rayed, 0.2–0.5 mm); blade obovate to oblong-spatulate, 0.2–0.6(–0.8) cm × 1–2(–3) mm, margins entire, surfaces often pubescent with simple and stalked, 2–5-rayed trichomes, 0.2–0.9 mm, sometimes glabrous and trichomes on margins only. |
Cauline leaves | 0. |
0. |
Racemes | 6–18-flowered, ebracteate, considerably elongated in fruit; rachis not flexuous, pubescent as stem. |
2–5-flowered, ebracteate, not or slightly elongated in fruit; rachis slightly 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. |
sepals (spreading or reflexed), oblong, 2–3.5 mm, pubescent, (trichomes simple and 2-rayed); petals yellow or purple, linear, 2.5–5 × 0.3–0.7 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, straight, 2–5(–7) mm, pubescent as stem. |
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). |
suborbicular, plane, inflated basally, flattened distally, 3–5 × 3–4 mm; valves glabrous or puberulent, trichomes simple, 0.02–0.3 mm; ovules 4–10 per ovary; style 0.2–0.6 mm. |
Seeds | (pale brown), ovoid, 0.9–1.3 × 0.6–0.9 mm. |
ovoid, 1–1.3 × 0.8–1 mm. |
2n | = 80. |
= 24, 64. |
Draba alpina |
Draba stenopetala |
|
Phenology | Flowering Jun–Aug. | Flowering May–Jul. |
Habitat | Moist tundra and ridges, sand and gravel flats or beaches | Rock outcrops, talus, rocky ridges, alpine tundra |
Elevation | 0-1000 m (0-3300 ft) | 100-1900 m (300-6200 ft) |
Distribution |
LB; MB; NU; ON; QC; Greenland; Europe (Finland, Norway, Russia, Sweden)
|
AK; YT; e Asia (Russian Far East) |
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.) |
Different chromosome counts for Draba stenopetala were reported as 2n = 24 from North America and 2n = 64 from the Russian Far East (S. I. Warwick and I. A. Al-Shehbaz 2006). It is unlikely that a single species is involved, and further work is needed to verify the counts from North America. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 7, p. 290. | FNA vol. 7, p. 341. |
Parent taxa | Brassicaceae > tribe Arabideae > Draba | Brassicaceae > tribe Arabideae > Draba |
Sibling taxa | ||
Synonyms | D. alpina var. hydeana, D. alpina var. inflatisiliqua | D. stenopetala var. purpurea |
Name authority | Linnaeus: Sp. Pl. 2: 642. (1753) | Trautvetter: Trudy Imp. S.-Petersburgsk. Bot. Sada 6: 11. (1879) |
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