Draba globosa |
Draba malpighiacea |
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beavertip Draba, rockcress Draba, round-fruit Draba |
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Habit | Perennials; (cespitose, pulvinate); caudex branched (with persistent leaves, branches sometimes terminating in sterile rosettes); scapose. | Perennials; caudex simple or branched (sometimes with persistent leaf bases); not scapose. |
Stems | unbranched, 0.1–0.5 dm, glabrous. |
unbranched, 0.5–1.5 dm, pubescent throughout, trichomes malpighiaceous, 0.2–0.5 mm, and sometimes simple. |
Basal leaves | rosulate; sessile; blade (not fleshy), narrowly oblanceolate or lanceolate to linear, (0.2–)0.3–0.8 cm × 0.5–1.6(–2) mm, margins entire (ciliate, trichomes simple, 0.1–0.8 mm, apex acute, trichomes usually longer), surfaces glabrous, (midvein obscure abaxially). |
rosulate; petiolate; petiole not ciliate; blade oblanceolate to spatulate, 0.5–1.8 cm × 2–4 mm, margins entire or dentate, (not ciliate proximally), surfaces pubescent with malpighiaceous trichomes, 0.3–0.6 mm. |
Cauline leaves | 0. |
4–13; sessile; blade broadly ovate to lanceolate, margins denticulate, surfaces pubescent as basal. |
Racemes | 2–5(–7)-flowered, ebracteate, slightly elongated in fruit; rachis not flexuous, glabrous. |
10–33-flowered, ebracteate, elongated in fruit; rachis not flexuous, glabrous or pubescent, trichomes simple and/or malpighiaceous. |
Flowers | sepals (persistent to near fruit maturity), ovate to broadly oblong, 2–3 mm, glabrous; petals white to pale yellow, obovate, 2.5–4 × 1.2–2 mm; anthers oblong, 0.4–0.6 mm. |
sepals ovate, 2.5–3 mm, subapically pubescent, (trichomes simple and malpighiaceous); petals yellow, oblanceolate, 4–5 × 1.5–2 mm; anthers oblong, 0.7–1 mm. |
Fruiting pedicels | divaricate-ascending, straight or slightly curved, 2–6 mm, glabrous. |
divaricate-ascending, straight or curved upward, 6–13 mm, pubescent abaxially, trichomes simple and/or malpighiaceous. |
Fruits | ovate, plane, flattened, 4.5–8 × 2.5–4 mm; valves (distinctly veined), glabrous; ovules 8–16 per ovary; style (0.1–)0.2–0.6 mm. |
elliptic to elliptic-lanceolate, plane, flattened, 5–10 × 1.5–2.2 mm; valves glabrous; ovules 14–18 per ovary; style 0.8–1.2 mm. |
Seeds | oblong, 1.1–1.4 × 0.8–1 mm. |
ovoid, 1–1.4 × 0.7–0.9 mm. |
Draba globosa |
Draba malpighiacea |
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Phenology | Flowering Jun–Aug. | Flowering Jun–Aug. |
Habitat | Ridges, talus, alpine tundra and meadows | Rock outcrops and rocky slopes in subalpine conifer forests |
Elevation | 2700-3900 m (8900-12800 ft) | 3000-3500 m (9800-11500 ft) |
Distribution |
ID; MT; UT; WY
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CO |
Discussion | Draba globosa is an apomictic species closely related to D. burkei (M. D. Windham, unpubl.). Though often treated as a variety of D. densifolia, it is morphologically and phyletically distinct from that species. Both R. C. Rollins (1993) and N. H. Holmgren (2005b) indicated that the species occurs in Colorado, but we have not seen material for that state. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Draba malpighiacea, which is restricted to higher elevations in Hinsdale, La Plata, and Montezuma counties, has been included within D. spectabilis by previous authors. Preliminary data suggest that it is one of the diploid parents of tetraploid D. spectabilis. It is readily distinguished from all species of Draba in Canada and the United States by having a leaf indumentum of exclusively malpighiaceous trichomes. The only other species in the flora area with such trichomes is D. sibirica, a stoloniferous, scapose perennial known only from Greenland. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 7, p. 308. | FNA vol. 7, p. 318. |
Parent taxa | Brassicaceae > tribe Arabideae > Draba | Brassicaceae > tribe Arabideae > Draba |
Sibling taxa | ||
Synonyms | D. apiculata, D. densifolia var. apiculata, D. densifolia var. decipiens, D. densifolia var. globosa | |
Name authority | Payson: Amer. J. Bot. 4: 257. (1917) | Windham & Al-Shehbaz: Harvard Pap. Bot. 12: 417. (2007) |
Web links |