Draba hitchcockii |
Draba corrugata |
|
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lost river Draba |
Southern California Draba |
|
Habit | Perennials; (densely cespitose); caudex branched (densely covered with persistent leaves, branches sometimes terminating in sterile rosettes); scapose. | Biennials or perennials; (short-lived); caudex simple (covered with persistent leaves); not scapose. |
Stems | unbranched, (0.1–)0.3–1(–1.3) dm, hirsute throughout, trichomes simple, 0.4–1 mm, and 2–4-rayed, 0.1–0.6 mm. |
branched, (0.3–) 0.4–1.7(–2.5) dm, pubescent throughout, trichomes simple and long-stalked, 2-rayed, 0.4–1.4 mm, with smaller, 2–4-rayed ones, 0.1–0.6 mm, (simple ones usually fewer distally). |
Basal leaves | (densely imbricate); rosulate; sessile; blade narrowly oblanceolate to oblong-linear, 0.3–1.2(–1.5) cm × 1–2 mm, margins entire, (ciliate, trichomes simple, 0.3–1.2 mm), surfaces pubescent abaxially with stalked, 2–4-rayed trichomes, 0.08–0.45 mm, (midvein obscure), adaxially glabrous proximally, sparsely pubescent distally with mostly simple trichomes. |
(densely imbricate); rosulate; shortly petiolate; petiole base and margin ciliate, (trichomes simple, 0.6–2 mm); blade oblong to narrowly oblanceolate, (0.5–)1–2.2(–4.5) cm × 2–5 mm, margins entire, surfaces densely pubescent, abaxially with stalked, 2–4-rayed trichomes, 0.4–1.2 mm, (simple trichomes often along midvein), adaxially with mostly simple and long-stalked, 2-rayed trichomes, 0.6–1.3 mm, sometimes with 3- or 4-rayed ones. |
Cauline leaves | 0. |
(4–)6–10(–13); sessile; blade oblong to ovate, margins entire, surfaces pubescent as basal. |
Racemes | 4–15-flowered, ebracteate, elongated in fruit; rachis not flexuous, hirsute as stem. |
(10–)18–55(–67)-flowered, ebracteate or proximalmost flowers bracteate, slightly or considerably elongated in fruit; rachis not flexuous, pubescent as stem. |
Flowers | sepals oblong, 2.5–3.5 mm, hirsute, (trichomes simple and stalked, 2–4-rayed); petals white, obovate, 5–6.5 × 2–3.5 mm; anthers ovate, 0.5–0.6 mm. |
sepals oblong, 2–2.7 mm, pubescent, (trichomes short-stalked, 2–4-rayed); petals yellow, linear, 2–3.5 × 0.2–0.5 mm; anthers oblong, 0.6–0.8 mm (exserted). |
Fruiting pedicels | ascending, straight, (2–)4–13(–18) mm, hirsute as stem. |
divaricate to ascending, straight, 2–6(–8) mm, pubescent as stem. |
Fruits | ovate to broadly oblong or elliptic, plane, flattened, (3–)4–7(–10) × (2.5–)3.5–5 mm; valves pubescent, trichomes simple and short-stalked, 2(–4)-rayed, 0.06–0.5 mm; ovules 8–12 per ovary; style (0.8–)1–1.7(–2) mm. |
elliptic to oblong or linear- to oblong-elliptic, slightly twisted or plane, flattened, 5–13(–17) × 2–3(–4) mm; valves pubescent, trichomes short-stalked, cruciform, 0.1–0.5 mm, (sometimes with 2- or 3-rayed ones); ovules 16–28 per ovary; style 1.4–3.4 mm. |
Seeds | oblong, 1.4–1.8 × 0.8–1 mm. |
oblong, 1–1.2 × 0.6–0.8 mm. |
2n | = 54. |
|
Draba hitchcockii |
Draba corrugata |
|
Phenology | Flowering May–Jun. | Flowering Jun–Jul. |
Habitat | Limestone outcrops and gravelly soil | Alpine fellfields, talus, open pine woodlands |
Elevation | 1800-2200 m (5900-7200 ft) | 2000-3500 m (6600-11500 ft) |
Distribution |
ID |
CA
|
Discussion | Draba hitchcockii is known from the Lost River Range in Butte and Custer counties. Based on morphological and chromosomal evidence, M. D. Windham (2004) suggested that it may be an allopolyploid resulting from hybridization between D. oreibata and D. paysonii. Draba hitchcockii is superficially similar to D. jaegeri, a taxon known from the Charleston Mountains of Clark County, Nevada. Both are cespitose perennials with relatively large, white flowers and a chromosome number (2n = 54) otherwise unknown in Draba (Windham). Features distinguishing these two taxa are provided in the discussion of 51. D. jaegeri. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Of conservation concern. Draba corrugata was broadly circumscribed by R. C. Rollins (1993) to include three varieties that we treat as distinct species. For a discussion of species limits and distinguishing features, see I. A. Al-Shehbaz and M. D. Windham (2007). Draba corrugata, in the strict sense, is known from the San Antonio, San Bernardino, and San Gabriel mountains in Los Angeles and San Bernardino counties. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 7, p. 311. | FNA vol. 7, p. 301. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | D. vestita | |
Name authority | Rollins: J. Arnold Arbor. 64: 500. (1983) | S. Watson: in W. H. Brewer et al., Bot. California 2: 430. (1880) |
Web links |