Draba alpina |
Draba sphaerocarpa |
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alpine Draba |
globefruit Draba |
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Habit | Perennials; (cespitose); caudex branched (covered with persistent leaves or leaf remains); scapose. | Perennials; caudex branched (branches loose or compact, 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, (0.15–)0.3–0.8(–1.1) dm, usually densely pubescent throughout, trichomes stalked, 2–5-rayed, 0.1–0.4 mm, with subsessile, smaller, 4–8-rayed ones, rarely proximally with some simple trichomes. |
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; petiole margin not ciliate; blade oblanceolate to obovate or linear-oblanceolate, (0.2–)0.3–0.9(–1.5) cm × 1–2.5(–4) mm, margins entire, (not ciliate), surfaces canescent with short-stalked, 8–15-rayed, stellate trichomes, 0.1–0.25 mm. |
Cauline leaves | 0. |
0. |
Racemes | 6–18-flowered, ebracteate, considerably elongated in fruit; rachis not flexuous, pubescent as stem. |
(4–)6–18(–23)-flowered, ebracteate, elongated in fruit; rachis not 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 oblong, 2–3.5 mm, pubescent, (trichomes 4–6-rayed); petals yellow or lemon, oblanceolate to spatulate, 4–6 × 1.5–3 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 to ascending, straight, 4–9(–13) 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). |
ellipsoid to ovoid, plane, inflated at least basally, 2–5(–6) × 1.5–2.5(–3.5) mm; valves pubescent, trichomes 2–4-rayed, 0.03–0.2 mm (some or all rays spurred); ovules 4–10(–12) per ovary; style 0.2–0.9(–1.2) mm. |
Seeds | (pale brown), ovoid, 0.9–1.3 × 0.6–0.9 mm. |
ovoid, 1–1.6 × 0.7–1.2 mm. |
2n | = 80. |
= 20. |
Draba alpina |
Draba sphaerocarpa |
|
Phenology | Flowering Jun–Aug. | Flowering May–Jul. |
Habitat | Moist tundra and ridges, sand and gravel flats or beaches | Granite outcrops and rocky slopes in open pine forests |
Elevation | 0-1000 m (0-3300 ft) | 2100-2800 m (6900-9200 ft) |
Distribution |
LB; MB; NU; ON; QC; Greenland; Europe (Finland, Norway, Russia, Sweden)
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ID |
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.) |
Draba sphaerocarpa is a distinctive species known only from Boise, Custer, Idaho, and Valley counties in central Idaho. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 7, p. 290. | FNA vol. 7, p. 339. |
Parent taxa | Brassicaceae > tribe Arabideae > Draba | Brassicaceae > tribe Arabideae > Draba |
Sibling taxa | ||
Synonyms | D. alpina var. hydeana, D. alpina var. inflatisiliqua | D. argyrea var. sphaerocarpa |
Name authority | Linnaeus: Sp. Pl. 2: 642. (1753) | J. F. Macbride & Payson: Amer. J. Bot. 4: 266. (1917) |
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