Draba alpina |
Draba cuneifolia |
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alpine Draba |
wedge leaf Draba |
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Habit | Perennials; (cespitose); caudex branched (covered with persistent leaves or leaf remains); scapose. | Annuals; scapose or subscapose. | ||||||||
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. |
(simple to many from or near base), unbranched, (0.2–) 0.3–2.7(–3.7) dm, hirsute or pubescent throughout, trichomes 3–4-rayed, 0.05–0.4 mm, (sometimes mixed proximally with simple or spurred ones, 0.5–1.2 mm). |
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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. |
not rosulate; petiole (obscure), not ciliate; blade oblanceolate to spatulate or broadly obovate, (0.4–)1–3.5(–5) cm × (2–)6–20(–28) mm, margins dentate (in distal 1/2), surfaces pubescent, abaxially with stalked, 2–4-rayed trichomes, 0.1–0.7 mm, adaxially similar or also with fewer, simple trichomes, 0.4–0.7 mm. |
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Cauline leaves | 0. |
0–6 (on proximal 1/3 of stem); blade similar to basal. |
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Racemes | 6–18-flowered, ebracteate, considerably elongated in fruit; rachis not flexuous, pubescent as stem. |
10–50(–70)-flowered (throughout or on distal 1/3 of scape), ebracteate, elongated in fruit; rachis not flexuous, densely pubescent, trichomes 2–4-rayed. |
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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. |
(late ones cleistogamous, apetalous); sepals (green or pink), oblong, 1.5–2.5 mm, glabrous or pubescent, (trichomes simple); petals white, spatulate, (2–)2.5–4.5(–5) × 1–2 mm, (emarginate or obtuse); anthers ovate to oblong, (0.1–)0.25–0.4 mm. |
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Fruiting pedicels | ascending to divaricate-ascending, straight or, sometimes, slightly curved upwards, 4–14(–30) mm, pubescent, trichomes simple and 2–4-rayed. |
horizontal to divaricate-ascending, straight, (1–)2–7(–10) mm, pubescent as rachis. |
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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). |
oblong to linear or lanceolate to broadly ovate, plane, flattened, (3–)6–12(–16) × 1.7–2.7(–3) mm; valves usually puberulent, rarely glabrous, trichomes simple, antrorse, 0.1–0.3 mm, (rarely with 2-rayed ones, or all trichomes short-stalked, 4-rayed, cruciform); ovules (12–)24–66(–72) per ovary; style 0.01–0.3(–0.4) mm. |
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Seeds | (pale brown), ovoid, 0.9–1.3 × 0.6–0.9 mm. |
broadly ovoid, 0.5–0.7 × 0.4–0.5 mm. |
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2n | = 80. |
= 30, 32. |
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Draba alpina |
Draba cuneifolia |
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Phenology | Flowering Jun–Aug. | |||||||||
Habitat | Moist tundra and ridges, sand and gravel flats or beaches | |||||||||
Elevation | 0-1000 m (0-3300 ft) | |||||||||
Distribution |
LB; MB; NU; ON; QC; Greenland; Europe (Finland, Norway, Russia, Sweden)
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AL; AR; AZ; CA; CO; FL; IL; KS; KY; LA; MO; MS; NC; NE; NM; NV; OH; OK; PA; SD; TN; TX; UT; n Mexico |
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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.) |
Varieties 3 (3 in the flora). Draba cuneifolia is highly variable in fruit shape and size, style length, ovule number per ovary, type of fruit indumentum, and length of the fruiting raceme in relation to the rest of the scape. Reported chromosome numbers also vary, but it is currently unclear whether this is the result of biologically relevant processes or erroneous counts. R. L. Hartman et al. (1975) divided the species into three varieties, a position followed by subsequent authors (e.g., R. C. Rollins 1993). Typical var. sonorae is rather distinct (see key below) and may deserve recognition as a separate species, as by O. E. Schulz (1927). Critical, population-based, molecular studies are needed to assess this. In the absence of such studies, we tentatively follow Hartman et al., recognizing three varieties that are distinguished primarily by the types of trichomes found on the fruits. Glabrous-fruited forms occasionally encountered in all three varieties can be difficult to identify. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 7, p. 290. | FNA vol. 7, p. 303. | ||||||||
Parent taxa | Brassicaceae > tribe Arabideae > Draba | Brassicaceae > tribe Arabideae > Draba | ||||||||
Sibling taxa | ||||||||||
Subordinate taxa | ||||||||||
Synonyms | D. alpina var. hydeana, D. alpina var. inflatisiliqua | |||||||||
Name authority | Linnaeus: Sp. Pl. 2: 642. (1753) | Nuttall ex Torrey & A. Gray: Fl. N. Amer. 1: 108. (1838) | ||||||||
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