Draba alpina |
Draba cruciata |
|
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alpine Draba |
Mineral King Draba |
|
Habit | Perennials; (cespitose); caudex branched (covered with persistent leaves or leaf remains); scapose. | Perennials; (cespitose, loosely matted); caudex branched (with persistent leaf remains, 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, (0.3–)0.5–1.4(–1.8) dm, often glabrous throughout, sometimes pubescent proximally, trichomes stalked, cruciform, 0.07–0.3 mm, with 3–5-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 ciliate throughout; blade oblanceolate to narrowly obovate, (0.4–)0.6–1.1(–1.6) cm × 1.5–3 mm, margins entire or minutely denticulate, surfaces pubescent with stalked, cruciform trichomes, 0.07–0.4 mm, (rarely with fewer, 3–5-rayed ones, sometimes both surfaces glabrous and only margins pubescent, not ciliate, midvein obscure abaxially). |
Cauline leaves | 0. |
0. |
Racemes | 6–18-flowered, ebracteate, considerably elongated in fruit; rachis not flexuous, pubescent as stem. |
(3–)5–18(–22)-flowered, ebracteate, considerably 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 mm, glabrous or pubescent distally, (trichomes short-stalked, 4-rayed); petals yellow, spatulate to oblanceolate, 4–5(–6) × 1.2–2 mm; anthers ovate, 0.4–0.6 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–)5–10(–13) 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). |
narrowly lanceolate to elliptic-lanceolate, plane (not curved), flattened, (4–)6–12(–16) × 1.5–3 mm; valves glabrous or puberulent, trichomes simple and short stalked, 2–4-rayed, 0.03–0.15 mm; ovules 6–10(–12) per ovary; style (0.1–)0.3–0.8 mm. |
Seeds | (pale brown), ovoid, 0.9–1.3 × 0.6–0.9 mm. |
ovoid, 1–1.7 × 0.8–1.3 mm. |
2n | = 80. |
|
Draba alpina |
Draba cruciata |
|
Phenology | Flowering Jun–Aug. | Flowering Jul–Aug. |
Habitat | Moist tundra and ridges, sand and gravel flats or beaches | Subalpine areas, ridges in pine and fir forests |
Elevation | 0-1000 m (0-3300 ft) | 2500-3100 m (8200-10200 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 cruciata is known only from the Sierra Nevada of Tulare County. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 7, p. 290. | FNA vol. 7, p. 303. |
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) | Payson: Amer. J. Bot. 4: 265. (1917) |
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