Draba scotteri |
Draba weberi |
|
---|---|---|
scotter's whitlowgrass |
weber's Draba |
|
Habit | Perennials; (cespitose); caudex simple or branched (covered with persistent leaves); scapose. | Perennials; (cespitose); caudex branched (covered with persistent, somewhat thickened, petioles); not scapose. |
Stems | unbranched, 0.2–1.4 dm, pubescent throughout, trichomes 2–8-rayed, 0.07–0.4 mm, and, sometimes, simple ones, 0.2–0.8 mm. |
unbranched, 0.2–0.6(–1) dm, glabrous or sparsely pubescent throughout, trichomes simple, sessile or subsessile, 2- or 3-rayed, 0.2–0.6 mm. |
Basal leaves | rosulate; petiolate; petiole base ciliate, (trichomes simple, 0.2–1 mm); blade oblanceolate, 0.4–1.5 cm × 1–3 mm, margins entire, (ciliate as petiole base), surfaces pubescent with short-stalked, stellate, 8–12-rayed trichomes, 0.1–0.4 mm. |
rosulate; petiolate; petiole margin ciliate, (trichomes simple, 0.2–0.6 mm); blade linear-oblanceolate, 0.4–1.5 cm × 0.8–1.7 mm, margins entire, (pubescent as petiole), surfaces pubescent abaxially with (appressed), simple, subsessile or sessile, 2–4-rayed trichomes, 0.1–0.4 mm, glabrous or subapically sparsely pubescent adaxially with simple trichomes. |
Cauline leaves | 0. |
1–3; sessile; blade linear-oblong, margins entire, surfaces pubescent as basal. |
Racemes | 1–9-flowered, usually ebracteate, rarely proximalmost flower subtended by a tiny bract, usually considerably elongated in fruit; rachis not flexuous, pubescent as stem. |
5–15-flowered, ebracteate, elongated in fruit; rachis not flexuous, glabrous or pubescent as stem. |
Flowers | sepals oblong, 2–3 mm, subapically pubescent, (trichomes simple); petals yellow, obovate to spatulate, 3.5–5.5 × 1.5–2.5 mm; anthers ovate, 0.4–0.5 mm. |
sepals ovate, 1.5–2 mm, pubescent, (trichomes simple and 2-rayed); petals yellow, spatulate, 3–4 × 1.2–1.8 mm, (flared, clawed); anthers ovate, 0.3–0.4 mm. |
Fruiting pedicels | divaricate-ascending, straight, 3–8(–12) mm, pubescent as stem. |
divaricate-ascending, straight, 2–6 mm, glabrous or sparsely pubescent as stem. |
Fruits | lanceolate to narrowly so, plane, flattened, 5–11 × 1.5–2.5 mm; valves pubescent, trichomes simple, 0.1–0.4 mm, occasionally with some 2-rayed ones; ovules 12–18 per ovary; style 0.3–1 mm. |
ovate, plane, flattened, 4–8 × 2–3 mm; valves glabrous; ovules 16–18 per ovary; style 0.2–0.3 mm. |
Seeds | ovoid, 0.8–1.2 × 0.6–0.7 mm. |
ovoid, 1–1.2 × 0.6–0.7 mm. |
2n | = 96. |
|
Draba scotteri |
Draba weberi |
|
Phenology | Flowering Jun–Jul. | Flowering Jun–Jul. |
Habitat | Talus and gravelly summits in alpine communities | Rock crevices along streamlets near timberline |
Elevation | 1200-2000 m (3900-6600 ft) | ca. 3500 m (ca. 11500 ft) |
Distribution |
YT |
CO |
Discussion | Of conservation concern. The description of Draba scotteri is based on collections from Kluane National Park, southwestern Yukon Territory. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Of conservation concern. Draba weberi is an apomictic species allied to D. exunguiculata, D. grayana, and D. streptobrachia. From those, it is distinguished by having ovate fruits, clawed petals, and sessile, 2–4-rayed trichomes with untwisted rays often appressed to leaf and stem surfaces. Draba weberi is known from near North Star Peak in central Colorado (Summit County). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 7, p. 335. | FNA vol. 7, p. 346. |
Parent taxa | ||
Sibling taxa | ||
Name authority | G. A. Mulligan: Canad. J. Bot. 57: 1874. (1979) | R. A. Price & Rollins: Harvard Pap. Bot. 1(3): 75, fig. 3. (1991) |
Web links |