Draba santaquinensis |
Draba subumbellata |
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mound Draba, parasol Draba |
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Habit | Biennials or perennials; (short-lived); caudex simple (poorly developed, without persistent leaf bases); not scapose. | Perennials; (cespitose, densely pulvinate); caudex branched (densely covered with persistent leaves and remains, branches tightly grouped, sometimes terminating in sterile rosettes); scapose. |
Stems | usually branched, 1.1–3.4 dm, hirsute proximally, trichomes mostly simple and 2-rayed, 0.2–1.5 mm, pubescent distally, trichomes mostly 2- or 3-rayed, 0.2–1 mm. |
unbranched, (0.05–)0.1–0.25 dm, densely pubescent throughout, trichomes (grayish), stalked, dendritic, 5–12-rayed, 0.1–0.25 mm. |
Basal leaves | rosulate; petiole (obscure), ciliate, (trichomes simple and 2-rayed); blade obovate to oblanceolate, 1.6–2.5 cm × 5–10 mm, margins usually entire, rarely denticulate, surfaces pubescent, abaxially with stalked, mostly cruciform trichomes, 0.5–1 mm, adaxially with simple and stalked, 2–4-rayed ones. |
(densely imbricate); rosulate; sessile; blade obovate to broadly oblong, 0.2–0.4 cm × 0.6–1.5 mm, margins entire, (not ciliate), surfaces densely pubescent, trichomes (grayish), stalked, dendritic, 5–12-rayed, 0.1–0.3 mm, (sometimes with long-stalked and spurred trichomes adaxially). |
Cauline leaves | usually 1–5; sessile or subsessile; blade oblanceolate to oblong, margins often denticulate, (ciliate proximally, with 2- or 3-rayed trichomes). |
0. |
Racemes | 9–25-flowered, ebracteate, elongated in fruit; rachis not flexuous, pubescent, trichomes 2- or 3-rayed. |
2–5(–10)-flowered, ebracteate, subumbellate or slightly elongated in fruit; rachis not flexuous, pubescent as stem. |
Flowers | sepals oblong-obovate, 2–3.5 mm, pubescent, (trichomes short- to long-stalked, 2–4-rayed, 0.2–0.8 mm); petals yellow (often fading whitish), oblanceolate, 3–5 × 1–1.5 mm; anthers ovate, 0.4–0.5 mm. |
sepals broadly oblong, 1.8–2.8 mm, pubescent, (trichomes dendritic); petals yellow, spatulate, 2.8–4 × 1–1.5 mm; anthers ovate, 0.3–0.4 mm. |
Fruiting pedicels | horizontal to divaricate-ascending, usually straight, rarely curved upward, 7–10 mm, pubescent, trichomes 2- or 3-rayed. |
divaricate-ascending, straight, 1.5–3(–6) mm, glabrous or pubescent as stem. |
Fruits | narrowly elliptic to slightly falcate, plane, flattened, (7–)10–16 × (2–)2.5–3.7 mm; valves pubescent, trichomes short-stalked, 2–4-rayed, 0.2–0.5 mm; ovules 14–22 per ovary; style 0.9–1.2 mm. |
ovoid to ovoid-lanceolate, plane, inflated and sometimes subgibbous basally, flattened distally, 2–5 × 2–3 mm; valves pubescent, trichomes short-stalked, dendritic, 4–12-rayed, (sometimes spurred), 0.05–0.2 mm; ovules 6–12 per ovary; style 0.2–0.6 mm. |
Seeds | oblong, 1.1–1.5 × 0.7–0.9 mm. |
oblong, 1–1.2 × 0.5–0.7 mm. |
2n | = 20. |
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Draba santaquinensis |
Draba subumbellata |
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Phenology | Flowering late Apr-early Jun. | Flowering Jul–Aug. |
Habitat | Limestone outcrops and rocky slopes in mixed conifer communities | Wind-eroded areas, alpine fellfields, rock crevices |
Elevation | 1800-2400 m (5900-7900 ft) | 3300-4100 m (10800-13500 ft) |
Distribution |
UT |
CA; NV |
Discussion | Although Draba santaquinensis was included within D. brachystylis by previous authors, I. A. Al-Shehbaz and M. D. Windham (2007) have shown that it is distinct both morphologically and chromosomally. It is currently known only from Utah County (American Fork, Provo, and Santaquin canyons) in north-central Utah. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Draba subumbellata is similar to, and sympatric with, D. oligosperma. It is distinguished from the latter by having stalked, stellate to dendritic leaf trichomes, subumbellate racemes, fruiting pedicels 1.5–3.0(–6.0) mm, fruits pubescent with mostly 4–12-rayed trichomes, and well-formed anthers and pollen. By contrast, D. oligosperma has sessile or subsessile, pectinately-branched leaf trichomes, elongated racemes, fruiting pedicels (2–)3–10(–13) mm, fruits glabrous or pubescent with simple and 2-rayed trichomes, and abortive anthers and/or pollen. Draba subumbellata is restricted to the White Mountains (Esmeralda County, Nevada, and Mono County, California) and to Coyote Ridge in the Sierra Nevada (Inyo County, California). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 7, p. 334. | FNA vol. 7, p. 343. |
Parent taxa | ||
Sibling taxa | ||
Name authority | Windham & Allphin: Harvard Pap. Bot. 12: 410. (2007) | Rollins & R. A. Price: Aliso 12: 25, figs. 1k–n, 4. (1988) |
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