Draba murrayi |
Draba crassifolia |
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kathul mountain Draba |
Rocky Mountain Draba, Rocky Mountain whitlow-grass, snowbed Draba, snowbed whitlow-grass, thick-leaf Draba |
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Habit | Perennials; (cespitose); caudex often branched (covered with persistent leaves or leaf remains, branches sometimes terminating in sterile rosettes); not scapose. | Annuals or perennials; (short-lived); caudex branched (when present); usually scapose. |
Stems | unbranched, (0.4–)0.9–2.7(–3.5) dm, pubescent proximally, glabrous distally, trichomes simple, 0.2–1 mm, and often smaller, fewer short-stalked, 2–4-rayed ones. |
unbranched or, rarely, branched distally, (0.1–)0.3–1.1(–1.5) dm, usually glabrous throughout, rarely pubescent proximally, trichomes simple, 0.3–0.7 mm. |
Basal leaves | rosulate; petiolate; petiole (0–0.7 cm), margin ciliate; blade oblanceolate to obovate, (0.3–)0.6–2.1(–2.8) cm × (1.5–)2.5–5(–9) mm, margins entire or sparsely denticulate, (ciliate, trichomes simple, 0.2–1.1 mm), surfaces pubescent with stalked, cruciform, and 2- or 3-rayed trichomes, (rays sometimes spurred), 0.1–0.6 mm, sometimes mostly simple trichomes adaxially. |
rosulate; petiolate; petiole ciliate throughout; blade oblanceolate to obovate, (0.2–) 0.5–2.5(–3) cm × (1–)2–4(–6) mm, margins usually entire, rarely denticulate, (sometimes ciliate), surfaces glabrous or sparsely pubescent, with simple and 2-rayed trichomes, 0.3–0.9 mm. |
Cauline leaves | 1–6; sessile; blade ovate or oblong to lanceolate, margins usually entire, rarely sparsely denticulate, surfaces pubescent as basal. |
usually 0, rarely 1; sessile; blade oblong to ovate, margins entire, surfaces glabrous. |
Racemes | 7–25-flowered, ebracteate, elongated in fruit; rachis not flexuous, glabrous. |
(2–)4–15(–25)-flowered, ebracteate, elongated in fruit; rachis slightly flexuous or straight, glabrous. |
Flowers | sepals ovate, 1.5–2.2 mm, pubescent, (trichomes simple and short-stalked, 2-rayed); petals white, obovate, 4–6 × 1.5–2.5 mm; anthers ovate, 0.4–0.5 mm. |
(chasmogamous, petaliferous); sepals (green or purplish), ovate, 1–2 mm, glabrous; petals yellow (often fading white), oblanceolate, 1.5–2.5(–3) × 0.5–1 mm; anthers ovate, 0.15–0.25 mm. |
Fruiting pedicels | divaricate-ascending, usually straight, rarely curved, (4–)7–18 mm, glabrous. |
horizontal to divaricate-ascending, usually straight, rarely curved upward, 3–8(–10) mm (subequaling or shorter than fruit), glabrous. |
Fruits | linear-lanceolate to narrowly elliptic, plane, flattened, 5–13 × 1.5–2 mm; valves glabrous; ovules 20–30 per ovary; style 0.6–1.5 mm. |
usually narrowly elliptic to lanceolate, rarely linear-lanceolate, plane, flattened, (3–)5–10 × 1.5–2.5 mm; valves glabrous; ovules (8–)16–24(–30) per ovary; style 0.02–0.1 mm. |
Seeds | oblong, 0.9–1.2 × ca. 0.5 mm. |
elliptic, 0.7–0.8 × 0.4–0.5 mm. |
2n | = 48. |
= 40. |
Draba murrayi |
Draba crassifolia |
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Phenology | Flowering Jun–Jul. | Flowering Jun–Sep. |
Habitat | Rock outcrops and talus, open forests, dry slopes, alluvial gravels | Rock outcrops and talus, subalpine meadows, alpine summits and tundra, bare snow-melt areas |
Elevation | 150-900 m (500-3000 ft) | (50-)1000-4300 m ((200-)3300-14100 ft) |
Distribution |
AK; YT |
AK; AZ; CO; ID; MT; NM; NV; UT; WA; WY; AB; BC; LB; NT; NU; QC; YT; Greenland; n Europe (Norway, Sweden)
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Discussion | Of conservation concern. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
M. D. Windham (2004) presented morphological and chromosomal data suggesting that Draba crassifolia is an allopolyploid produced by hybridization between D. albertina and D. fladnizensis. Although the species is distinctive in large part, some individuals can be difficult to place and there is evidence of rare backcrossing (Windham, unpubl.). The attribution to Arizona is based on Schaack 345 (US) and Kearney & Peebles 12156 (US), both collected on the San Francisco Peaks in Coconino County. Draba crassifolia is found at elevations as low as 50 m in Greenland and the islands of Nunavut. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 7, p. 321. | FNA vol. 7, p. 302. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | D. crassifolia var. parryi, D. parryi | |
Name authority | G. A. Mulligan: Canad. J. Bot. 57: 1874. (1979) | Graham: Edinburgh New Philos. J. 7: 182. (1829) |
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