Draba scotteri |
Draba standleyi |
|
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scotter's whitlowgrass |
Standley's Draba |
|
Habit | Perennials; (cespitose); caudex simple or branched (covered with persistent leaves); scapose. | Perennials; (densely pulvinate); caudex branched (with persistent, thickened petioles, branches compact); 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, 0.3–1.3(–1.7) dm, usually glabrous throughout or sparsely pubescent proximally, rarely sparsely pubescent distally, trichomes simple and 2-rayed, 0.1–0.7 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. |
(not imbricate); rosulate; petiolate; petiole ciliate, (trichomes usually simple, rarely 2-rayed, not setiform); blade narrowly oblanceolate to linear-lanceolate, (strongly differentiated into blade and petiole), (1.2–)1.8–6(–8.5) cm × 1–5(–7) mm, margins entire or sparsely denticulate, (ciliate as petiole; midvein not prominent), surfaces glabrous or pubescent, usually with simple trichomes 0.1–0.8 mm, rarely 2-rayed. |
Cauline leaves | 0. |
1–8; sessile; blade lanceolate to narrowly oblong, margins usually 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. |
5–17(–23)-flowered, ebracteate, elongated in fruit; rachis not flexuous, usually glabrous, rarely pubescent, trichomes simple and 2-rayed, (non-crisped). |
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, 2–2.5 mm, pubescent, (trichomes simple); petals yellow, oblanceolate, 4–6 × 1.5–2 mm; anthers oblong, 0.6–0.8 mm. |
Fruiting pedicels | divaricate-ascending, straight, 3–8(–12) mm, pubescent as stem. |
divaricate-ascending or ascending, straight, 3–9(–13) mm, usually glabrous, rarely sparsely pubescent, trichomes simple. |
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. |
linear-elliptic to elliptic, twisted or plane, flattened, 5–10(–13) × 1.5–2.5 mm; valves usually glabrous, rarely puberulent, trichomes simple, 0.05–0.1 mm; ovules 12–24 per ovary; style 0.7–1.4(–1.8) mm. |
Seeds | ovoid, 0.8–1.2 × 0.6–0.7 mm. |
ovoid, 1–1.2 × 0.7–0.8 mm. |
2n | = 96. |
|
Draba scotteri |
Draba standleyi |
|
Phenology | Flowering Jun–Jul. | Flowering Jun–Aug. |
Habitat | Talus and gravelly summits in alpine communities | Igneous rock outcrops, stabilized talus slopes |
Elevation | 1200-2000 m (3900-6600 ft) | 1800-3100 m (5900-10200 ft) |
Distribution |
YT |
AZ; NM; TX |
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 standleyi is a distinctive species that is sporadically distributed in the mountains of southwestern United States. It is known from the Chiricahua Mountains (Cochise County, southeastern Arizona), the Organ Mountains and Black Range (Dona Ana and Sierra counties, south-central New Mexico), and the Davis Mountains (Jeff Davis County, western Texas). It has not been reported from Mexico, though it is very likely to occur there. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 7, p. 335. | FNA vol. 7, p. 340. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | D. gilgiana, D. chrysantha var. gilgiana | |
Name authority | G. A. Mulligan: Canad. J. Bot. 57: 1874. (1979) | J. F. Macbride & Payson: Ann. Missouri Bot. Gard. 5: 150. (1918) |
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