Draba scotteri |
Draba oxycarpa |
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scotter's whitlowgrass |
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Habit | Perennials; (cespitose); caudex simple or branched (covered with persistent leaves); scapose. | Perennials; (cespitose); caudex branched (covered with persistent petiole remains); 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, 0.2–1.1 dm, pubescent proximally, trichomes short-stalked, 2–5-rayed, 0.1–0.5 mm, (some rays spurred). |
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 base and margin ciliate, (trichomes simple, 0.3–1 mm); blade oblanceolate to lanceolate, 0.8–2.2 cm × 2–6 mm, margins often entire, surfaces pubescent abaxially with stalked, 2–5-rayed, stellate trichomes, 0.1–0.4 mm, often some rays spurred and trichomes appearing subdendritic, rarely glabrate, or with simple and 2-rayed ones, (midvein obscure abaxially, not thickened), adaxially glabrous or sparsely pubescent with simple trichomes, sometimes with long-stalked, 2- or 3-rayed ones. |
Cauline leaves | 0. |
0. |
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. |
(2–)4–13-flowered, ebracteate, (subcorymbose), not elongated in fruit; rachis not flexuous, 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 (grayish white), ovate to broadly so, 2.5–3 mm, pubescent, (trichomes simple and stalked, 2-rayed); petals creamy white to yellow, broadly obovate, 3.5–5 × 2.5–3.5 mm; anthers ovate, 0.4–0.5 mm. |
Fruiting pedicels | divaricate-ascending, straight, 3–8(–12) mm, pubescent as stem. |
subhorizontal to divaricate-ascending (not appressed to rachis), often slightly curved upward, 4–7(–10) mm, pubescent, trichomes simple (0.4–1 mm), and 2–4-rayed (0.1–0.4 mm). |
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 to ovate-oblong, plane, flattened, 5–10 × 3–5 mm; valves puberulent along replum, trichomes simple, 0.1–0.3 mm; ovules (16–)18–28 per ovary; style 0.2–0.6 mm (stigma as wide as style). |
Seeds | ovoid, 0.8–1.2 × 0.6–0.7 mm. |
(black), ovoid, 1–1.3 × 0.6–0.8 mm. |
2n | = 96. |
= 64. |
Draba scotteri |
Draba oxycarpa |
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Phenology | Flowering Jun–Jul. | Flowering Jun–Jul. |
Habitat | Talus and gravelly summits in alpine communities | Rocky soils |
Elevation | 1200-2000 m (3900-6600 ft) | |
Distribution |
YT |
Greenland; Europe (Norway [including Spitsbergen], Sweden); Atlantic Islands (Iceland) |
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.) |
Draba oxycarpa is an octoploid that most closely resembles the decaploid D. alpina. It is distinguished from that species by having creamy white to pale yellow (versus bright yellow) petals, gray-green (versus purplish tinged) sepals, petals 2.5–3.5 (versus 1.7–2.5) mm wide, stems pubescent proximally with primarily branched (versus primarily simple) trichomes, nearly black (versus pale brown) seeds, and ovate to ovate-oblong (versus elliptic) fruits 3–5 (versus 2–3) mm wide. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 7, p. 335. | FNA vol. 7, p. 325. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | D. alpina var. oxycarpa, D. gredinii | |
Name authority | G. A. Mulligan: Canad. J. Bot. 57: 1874. (1979) | Sommerfelt: Mag. Naturvidensk., n. s. 1: 240. (1833) |
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