Draba sibirica |
Draba grayana |
|
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Siberian whitlowgrass |
Gray's Draba |
|
Habit | Perennials; (stoloniferous); caudex branched (sparsely covered with persistent petiole remains, branches slender, creeping); scapose. | Perennials; (densely cespitose); caudex branched (covered with persistent, somewhat thickened, dry petioles); not scapose. |
Stems | (subdecumbent when sterile), unbranched, 0.5–2.5 dm, sparsely to densely hispid, trichomes malpighiaceous, (flowering scapes sparsely pilose proximally with simple trichomes, often glabrous on distal 1/2). |
unbranched, 0.08–0.6 dm, densely to moderately pubescent throughout, trichomes simple and stalked, 2- or 3-rayed, 0.2–1 mm. |
Basal leaves | rosulate; petiolate; blade oblong-lanceolate or oblanceolate, 0.4–2.2 cm × 1–5(–10) mm, margins entire, surfaces often pubescent, sometimes glabrous (except margins), with appressed, malpighiaceous trichomes (these sometimes with 1 or 2 shorter, lateral branches, appearing 3-fid or cross-shaped). |
rosulate; petiolate; petiole ciliate, (trichomes simple, 0.2–1 mm); blade linear to linear-oblanceolate, (0.4–)0.6–1.5(–2) cm × 1–2 mm, margins entire, (pubescent as petiole), surfaces pubescent abaxially with simple and stalked, 2- or 3-rayed trichomes, 0.1–0.4 mm, adaxially glabrate or subapically sparsely pubescent with simple trichomes. |
Cauline leaves | 0. |
1–4; sessile; blade linear to linear-oblanceolate, margins entire, surfaces pubescent as basal. |
Racemes | 7–20-flowered, ebracteate, considerably elongated in fruit; rachis not flexuous (straight), glabrous. |
5–12(–16)-flowered, usually ebracteate, rarely proximalmost flowers bracteate, slightly elongated in fruit; rachis not flexuous, pubescent as stem. |
Flowers | sepals (erect), oblong or ovate, 2–2.7 mm (lateral pair subsaccate basally), glabrous or abaxially sparsely pilose, (trichomes simple); petals yellow, narrowly obovate, 4–6 × 2–3 mm, (apex emarginate); anthers ovate-subcordate, 0.4–0.5 mm. |
sepals ovate, 1.5–2 mm, pubescent, (trichomes simple and short-stalked, 2- or 3-rayed); petals bright yellow, spatulate, 3–4.5 × 1–2 mm, (flared, clawed); anthers ovate, 0.3–0.5 mm. |
Fruiting pedicels | divaricate, straight or curved, (often filiform), 5–18(–23) mm, glabrous. |
divaricate-ascending, straight or slightly curved upward, 1.5–6 mm, pubescent as stem. |
Fruits | usually oblong to elliptic, rarely sublinear, plane, flattened, 4–8 × 1.5–2.2 mm; valves glabrous, (obscurely veined); ovules 24–30 per ovary; style 0.5–1 mm. |
lanceolate to oblong-lanceolate, slightly twisted or plane, flattened, 4–12 × 1.5–3 mm; valves glabrous or pubescent, trichomes simple, 0.07–0.2 mm; ovules 16–20 per ovary; style 0.4–1.2 mm. |
Seeds | (brown), ovoid, 0.9–1.2 × 0.5–0.6 mm. |
ovoid, 1–1.4 × 0.7–1 mm. |
2n | = 16. |
= 24 ± 3. |
Draba sibirica |
Draba grayana |
|
Phenology | Flowering May–Jul. | Flowering Jul–Aug. |
Habitat | Wet places on rocky slopes | Alpine tundra, fellfields, gravelly wet meadows |
Elevation | 0-300 m (0-1000 ft) | 3500-4000 m (11500-13100 ft) |
Distribution |
Greenland; Europe (Russia); Asia (Caucasus, Iran, Russian Far East, Siberia, Turkey, central republics) |
CO |
Discussion | Draba sibirica is one of three species of the genus in North America exhibiting malpighiaceous trichomes. It is easily distinguished from others (D. malpighiacea and some plants of D. spectabilis) by a complete absence of cauline leaves. It is found in the flora area in northeastern Greenland. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Of conservation concern. Draba grayana is an apomictic species clearly related to D. exunguiculata, with which it is occasionally sympatric (see discussion of 36. D. exunguiculata for distinguishing features). It is known from Chaffe, Clear Creek, Larimer, Park, and Summit counties. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 7, p. 337. | FNA vol. 7, p. 310. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | Lepidium sibiricum, D. gmelinii, D. repens, D. sibirica subsp. arctica | D. streptocarpa var. grayana, D. alpicola |
Name authority | (Pallas) Thellung: Neue Denkschr. Schweiz. Naturf. Ges. 41: 318. (1907) | (Rydberg) C. L. Hitchcock: Revis. Drabas W. N. Amer., 29. (1941) |
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