Draba helleriana |
Draba pectinipila |
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Heller's Draba |
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Habit | Biennials or perennials; (short-lived); caudex simple or branched; not scapose. | Perennials; (cespitose, sometimes forming mats); caudex branched (with persistent leaf bases, branches creeping, terminating in scapes or sterile rosettes); scapose. |
Stems | branched, (0.1–)1.5–4.3(–5.1) dm, hirsute throughout, trichomes simple, 0.4–1.3(–1.8) mm, with short-stalked to subsessile, 3–5-rayed ones, 0.2–0.4 mm, (some slightly coarser, 2-rayed). |
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). |
Basal leaves | rosulate; petiolate; petiole base ciliate or not; blade oblanceolate to obovate, 0.9–4.1(–5.2) cm × 2–7(–10) mm, margins entire or dentate, surfaces pubescent, abaxially with stalked, cruciform, and fewer 3–5-rayed trichomes, 0.1–0.6 mm, adaxially with cruciform and simple trichomes, 0.4–1.3 mm, and smaller 2-rayed ones. |
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. |
Cauline leaves | (8–)12–31(–43); sessile; blade ovate to lanceolate or oblong, margins usually dentate, rarely subentire, surfaces pubescent as basal. |
0. |
Racemes | 10–52(–83)-flowered, usually ebracteate, rarely proximalmost 1 or 2 flowers bracteate, elongated in fruit; rachis not flexuous, pubescent as stem. |
5–22-flowered, ebracteate, considerably elongated in fruit; rachis not flexuous, pubescent as stem. |
Flowers | sepals oblong, 2.5–4 mm, pubescent, (trichomes simple and stalked, 2-rayed); petals yellow, oblanceolate, 5–7 × 1.5–2.2 mm; anthers oblong, 0.5–0.8 mm. |
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. |
Fruiting pedicels | horizontal to divaricate-ascending, straight or slightly curved upward, 4–10(–13) mm, pubescent as rachis abaxially, glabrous adaxially. |
divaricate-ascending, straight, (5–)7–14 mm, sparsely pubescent, trichomes pectinate. |
Fruits | (not appressed to rachis), lanceolate to ovate or oblong-lanceolate, slightly to strongly twisted or plane, flattened, 5–15 × 2–3.5 mm; valves puberulent, trichomes simple and subsessile, 2(–4)-rayed, 0.03–0.25(–0.8) mm; ovules 14–28 per ovary; style (1–)1.5–3.5 mm. |
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. |
Seeds | oblong, 1–1.3 × 0.6–0.8 mm. |
oblong, 1.1–1.5 × 0.6–0.8 mm. |
2n | = 18. |
= 22. |
Draba helleriana |
Draba pectinipila |
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Phenology | Flowering Jun–Sep. | Flowering Apr–Jun. |
Habitat | Oak and pine-fir woodlands, aspen groves, rocky meadows | Rocky slopes in sagebrush scrub and pinyon-juniper woodlands |
Elevation | 2100-3600 m (6900-11800 ft) | 1700-2400 m (5600-7900 ft) |
Distribution |
AZ; CO; NM; Mexico (Nuevo León)
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CO; MT; UT; WY |
Discussion | Draba helleriana is highly variable and was divided by C. L. Hitchcock (1941) into four varieties. For a discussion of those and the circumscription of the species, see I. A. Al-Shehbaz and M. D. Windham (2007). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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.) |
Source | FNA vol. 7, p. 311. | FNA vol. 7, p. 328. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | D. aurea var. tylosa, D. helleriana var. leiocarpa, D. helleriana var. neomexicana, D. helleriana var. patens, D. helleriana var. pinetorum, D. neomexicana, D. neomexicana var. robusta, D. pallida, D. patens, D. pinetorum, D. stylosa | D. juniperina, D. oligosperma var. juniperina, D. oligosperma var. pectinipila |
Name authority | Greene: Pittonia 4: 17. (1899) | Rollins: Rhodora 55: 231. (1953) |
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