Draba pectinipila |
Draba subumbellata |
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mound Draba, parasol Draba |
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Habit | Perennials; (cespitose, sometimes forming mats); caudex branched (with persistent leaf bases, branches creeping, terminating in scapes or sterile rosettes); scapose. | Perennials; (cespitose, densely pulvinate); caudex branched (densely covered with persistent leaves and remains, branches tightly grouped, sometimes terminating in sterile rosettes); scapose. |
Stems | unbranched, (0.3–)0.4–1.6(–1.9) dm, pubescent, trichomes sessile, pectinate, 0.1–0.4 mm, (parallel to long axis of stem, sometimes with irregularly 2–4-rayed ones, 0.2–0.6 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; subsessile; blade narrowly oblanceolate to linear, (0.4–)0.6–1.3(–2) cm × 0.9–2.2 mm, margins entire (not ciliate), surfaces pubescent with subsessile or sessile, pectinate trichomes, 0.2–0.5 mm. |
(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 | 0. |
0. |
Racemes | 5–22-flowered, ebracteate, considerably elongated in fruit; rachis not flexuous, pubescent as stem. |
2–5(–10)-flowered, ebracteate, subumbellate or slightly elongated in fruit; rachis not flexuous, pubescent as stem. |
Flowers | sepals broadly ovate, 2–3.2 mm, pubescent, (trichomes pectinate); petals yellow, obovate to spatulate, 4–6.5 × 1.5–2.5 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 | divaricate-ascending, straight, (5–)7–14 mm, sparsely pubescent, trichomes pectinate. |
divaricate-ascending, straight, 1.5–3(–6) mm, glabrous or pubescent as stem. |
Fruits | ovoid, plane, slightly inflated basally, 4–6(–7) × 2–3 mm; valves pubescent, trichomes usually sessile, pectinate, 0.2–0.5 mm, rarely with simple ones; ovules 4–8 per ovary; style 0.5–1.5 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 × 0.6–0.8 mm. |
oblong, 1–1.2 × 0.5–0.7 mm. |
2n | = 22. |
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Draba pectinipila |
Draba subumbellata |
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Phenology | Flowering Apr–Jun. | Flowering Jul–Aug. |
Habitat | Rocky slopes in sagebrush scrub and pinyon-juniper woodlands | Wind-eroded areas, alpine fellfields, rock crevices |
Elevation | 1700-2400 m (5600-7900 ft) | 3300-4100 m (10800-13500 ft) |
Distribution |
CO; MT; UT; WY |
CA; NV |
Discussion | Draba pectinipila was treated as a synonym of D. oligosperma by G. A. Mulligan (1972), R. C. Rollins (1993), and N. H. Holmgren (2005b). The latter recognized D. juniperina as a distinct species but overlooked the fact that it is indistinguishable from the type collections of the earlier-published D. pectinipila. The species (including D. juniperina) differs significantly from D. oligosperma in both chromosome number and morphology. Draba pectinipila is easily distinguished by having fruit valves pubescent with pectinate trichomes, fruiting pedicels (5–)7–14 mm, petals 4–6.5 mm, ovules 4–8 per ovary, and styles 0.5–1.5 mm. By contrast, D. oligosperma has fruit valves glabrous or pubescent with simple or 2-rayed trichomes, fruiting pedicels (2–)3–10(–13) mm, petals 2.5–4 mm, ovules 6–12 per ovary, and styles 0.1–0.8(–1.1) mm. Draba pectinipila was previously known only from the type locality in northwestern Wyoming (Park County). Its range is now expanded to include that of D. juniperina in northwestern Colorado (Moffat County), northeastern Utah (Daggett and Uintah counties), and southwestern Wyoming (Sweetwater County). The record from Uintah County is based on Goodrich 22275 (NY). (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. 328. | FNA vol. 7, p. 343. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | D. juniperina, D. oligosperma var. juniperina, D. oligosperma var. pectinipila | |
Name authority | Rollins: Rhodora 55: 231. (1953) | Rollins & R. A. Price: Aliso 12: 25, figs. 1k–n, 4. (1988) |
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