Draba ramulosa |
Draba cyclomorpha |
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Tushar Mountain Draba |
granite Draba, Lemmon's Draba |
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Habit | Perennials; (loosely matted, grayish); caudex branched (with persistent leaf bases, branches creeping, sometimes terminating in sterile rosettes); not scapose. | Perennials; (cespitose, not pulvinate); caudex branched (with persistent petiole remains, branches sometimes terminating in sterile rosettes); scapose. |
Stems | unbranched, 0.4–0.6 dm, densely pubescent throughout, trichomes dendritic, 3–6-rayed, (often crisped), 0.1–0.4 mm. |
unbranched, 0.1–0.6(–1) dm, (thinly) pilose throughout, trichomes simple and stalked, 2- (or 3-)rayed, (often crisped), 0.1–0.8 mm. |
Basal leaves | (imbricate); not rosulate; sessile; blade obovate to oblanceolate, 0.4–1.1 cm × 2–3.2 mm, margins entire, (base and margins not ciliate), surfaces pubescent with stalked, 4–8-rayed trichomes, 0.1–0.5 mm, (sometimes 1 or more rays spurred), adaxially sometimes trichomes simple. |
rosulate; shortly petiolate; petiole base and margin ciliate, (trichomes simple, 0.2–1 mm); blade (somewhat fleshy), oblanceolate to obovate, 0.4–1 cm × 2–5 mm, margins entire, surfaces glabrous or hirsute, abaxially usually with stalked, 2-rayed trichomes, 0.1–0.6 mm, rarely with fewer, simple ones, (midvein obscure), adaxially with almost exclusively simple trichomes, to 0.6 mm. |
Cauline leaves | 2 or 3 (sometimes basal leaves spaced, flowering stem appearing to 8-leaved); sessile; blade oblong to ovate, margins entire, surfaces pubescent as basal. |
0. |
Racemes | 4–15-flowered, ebracteate or proximalmost 1 or 2 flowers bracteate, slightly elongated in fruit; rachis not flexuous, pubescent as stem. |
5–14(–20)-flowered, ebracteate, elongated in fruit; rachis not flexuous, pubescent as stem. |
Flowers | sepals broadly ovate, 1.7–2.4 mm, pubescent, (trichomes short-stalked, 2–5-rayed); petals yellow, obovate to oblanceolate, 3–4.5 × 1.5–2.5 mm; anthers ovate, 0.4–0.5 mm. |
sepals ovate, 1.5–2.2 mm, pubescent, (trichomes simple and short-stalked, 2-rayed); petals yellow, spatulate, 4–5.5 × 1.5–2.5 mm; anthers oblong, 0.6–0.7 mm. |
Fruiting pedicels | divaricate-ascending, usually straight, rarely curved upward, 3–6(–10) mm, pubescent, trichomes 3–6-rayed, (crisped, 0.1–0.4 mm), and, sometimes, simple. |
horizontal to divaricate-ascending, often curved upward or straight, 3–8(–10) mm, pilose as stem. |
Fruits | (not appressed to rachis), ovate to elliptic, plane, flattened, 4–6.5 × 2.5–4 mm; valves densely pubescent, trichomes simple and short-stalked, 2–5-rayed, 0.08–0.35 mm; ovules 6–12 per ovary; style (0.1–)0.3–0.7 mm. |
oblong to oblong-ovate, plane, flattened, 3.5–9 × 2.5–4 mm; valves glabrous; ovules 8–12 per ovary; style 0.3–1 mm. |
Seeds | oblong, 1.4–1.8 × 0.8–1.2 mm. |
ovoid, 1.4–1.9 × 1–1.2 mm. |
Draba ramulosa |
Draba cyclomorpha |
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Phenology | Flowering Jun–Aug. | Flowering Jul–Aug. |
Habitat | Rock outcrops, talus, gravelly soils | Basaltic talus, stony ridges |
Elevation | 3300-3600 m (10800-11800 ft) | 2500-3100 m (8200-10200 ft) |
Distribution |
UT |
OR |
Discussion | Of conservation concern. Molecular and chromosomal data (M. D. Windham, unpubl.) strongly suggest that Draba ramulosa is an allopolyploid species. It is thought to have originated through hybridization between D. sobolifera and a member of the white-flowered, euploid lineage of M. A. Beilstein and M. D. Windham (2003). It is easily distinguished from D. sobolifera by having pale yellow to whitish (versus bright yellow) petals, grayish (versus green) foliage, non-ciliate (versus ciliate) basal leaves pubescent with 4–8-rayed (versus 2–4-rayed) trichomes, often proximally bracteate (versus ebracteate) racemes, and flattened (versus inflated basally) fruits. Draba ramulosa is known from the Tushar Mountains in south-central Utah (Beaver and Piute counties). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Draba cyclomorpha was treated by Schulz, C. L. Hitchcock (1941), and R. C. Rollins (1993) as a variety of D. lemmonii. The two taxa are quite distinct morphologically and separated by nearly 1600 kilometers, justifying their treatment as distinct species (I. A. Al-Shehbaz and M. D. Windham 2007). Draba cyclomorpha is known to us only from the Wallowa Mountains. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 7, p. 332. | FNA vol. 7, p. 305. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | D. lemmonii var. cyclomorpha | |
Name authority | Rollins: Contr. Gray Herb. 214: 6. (1984) | Payson: Amer. J. Bot. 4: 263. (1917) |
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