Draba alpina |
Draba monoensis |
|
---|---|---|
alpine Draba |
Mono Draba, White Mountains. Draba |
|
Habit | Perennials; (cespitose); caudex branched (covered with persistent leaves or leaf remains); scapose. | Perennials; (usually cespitose); caudex simple or branched (poorly developed, with persistent leaf remains); sometimes 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–)0.1–0.4 dm, usually pubescent throughout, rarely sparsely pubescent or glabrous distally, trichomes simple and 2-rayed, (often crisped), 0.1–0.6 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. |
rosulate; subsessile or shortly petiolate; petiole margin ciliate or not; blade narrowly oblanceolate, (0.3–)0.5–1.6(–2) cm × (1–)1.5–3(–4) mm, margins usually entire, rarely subapically denticulate, (ciliate or not), surfaces pubescent with simple and stalked, 2-rayed trichomes, 0.1–0.7 mm, (midvein obscure abaxially). |
Cauline leaves | 0. |
0–2 (or 3); sessile; blade ovate to oblong, margins entire, surfaces pubescent as basal. |
Racemes | 6–18-flowered, ebracteate, considerably elongated in fruit; rachis not flexuous, pubescent as stem. |
(3–)6–13(–17)-flowered, ebracteate or proximalmost 1 (or 2) flowers bracteate, not or slightly elongated in fruit; rachis not flexuous, usually pubescent as stem, rarely 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 (persistent), oblong, 1–1.5 mm, subapically sparsely pubescent, (trichomes simple); petals white, spatulate, 1.5–2 × 0.5–0.6 mm; anthers ovate, 0.15–0.2 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, 1–2.5(–4) mm, usually pubescent as stem, rarely 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). |
ovoid to subellipsoid, plane, slightly inflated basally, (2–)3–5 × (1.2–)1.5–2.5 mm; valves usually puberulent, rarely glabrous, trichomes simple, 0.05–0.2 mm; ovules 12–20 per ovary; style 0.1–0.2 mm. |
Seeds | (pale brown), ovoid, 0.9–1.3 × 0.6–0.9 mm. |
ovoid, 0.6–0.8 × 0.4–0.6 mm. |
2n | = 80. |
|
Draba alpina |
Draba monoensis |
|
Phenology | Flowering Jun–Aug. | Flowering Jul–Aug. |
Habitat | Moist tundra and ridges, sand and gravel flats or beaches | Gravelly alpine meadows |
Elevation | 0-1000 m (0-3300 ft) | 3600-4000 m (11800-13100 ft) |
Distribution |
LB; MB; NU; ON; QC; Greenland; Europe (Finland, Norway, Russia, Sweden)
|
CA |
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. Draba monoensis appears to be polyploid (M. D. Windham, unpubl.), and its morphological similarity to D. fladnizensis (R. C. Rollins 1993) may indicate that the latter is one of its progenitors. The species is known from the White Mountains of Mono County. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 7, p. 290. | FNA vol. 7, p. 320. |
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) | Rollins & R. A. Price: Aliso 12: 22, figs. 1f–j, 3. (1988) |
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