Draba hitchcockii

Rollins

J. Arnold Arbor. 64: 500. 1983.

IllustratedEndemic
Treatment appears in FNA Volume 7. Treatment on page 311. Mentioned on page 288, 312, 314.

Perennials; (densely cespitose); caudex branched (densely covered with persistent leaves, branches sometimes terminating in sterile rosettes); 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. 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. Cauline leaves 0. Racemes 4–15-flowered, ebracteate, elongated in fruit; rachis not flexuous, hirsute as stem. Fruiting pedicels ascending, straight, (2–) 4–13 (–18) mm, hirsute 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. 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. Seeds oblong, 1.4–1.8 × 0.8–1 mm. 2n = 54.


Phenology: Flowering May–Jun.
Habitat: Limestone outcrops and gravelly soil
Elevation: 1800-2200 m

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.

Selected References

None.

Lower Taxa

None.

"elongated" is not a number."thick" is not a number.

... more about "Draba hitchcockii"
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.06 cm0.6 mm <br />6.0e-4 m <br />) +
Ihsan A. Al-Shehbaz +, Michael D. Windham +  and Reidar Elven +
Rollins +
appendaged +  and unappendaged +
1.2 cm12 mm <br />0.012 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
not +  and auriculate +
0.3 cm3 mm <br />0.003 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
lobed +, toothed +  and entire +
narrowly oblanceolate;oblong-linear +
much smaller +  and reduced +
0.1 cm1 mm <br />0.001 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
urceolate +, campanulate +  and tubular +
scapose +  and branched +
sessile +  and petiolate +
well-developed +
distinct +
well-differentiated +
emarginate +  and entire +
1800-2200 m +
straight +  and curved +
not winged +  and unappendaged +
connate +  and distinct +
not basally +  and dilated +
actinomorphic +
orange;purple;orange;purple;pink;white;yellow +
spreading +, ascending +  and erect +
linear +, oblanceolate +, spatulate +, obovate +, subsaccate +, not saccate +, oblong +  and ovate +
latiseptate +, twisted +  and sessile +
0.7 cm7 mm <br />0.007 m <br /> (1 cm10 mm <br />0.01 m <br />) +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
indehiscent +  and dehiscent +
0.4 cm4 mm <br />0.004 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
flattened +, plane +, ovate +  and broadly oblong or elliptic +
0.35 cm3.5 mm <br />0.0035 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
Limestone outcrops and gravelly soil +
sessile +  and petiolate +
alternate +, not +  and rosulate +
cauline +  and basal +
connate +  and distinct +
decurrent +
pinnatifid +
tenuinucellate +, crassinucellate +  and bitegmic +
campylotropous +  and anatropous +
5mm;6.5mm +
rudimentary +
obovate +
0.2 cm2 mm <br />0.002 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
Flowering May–Jun. +
trinucleate +  and 3(-11)-colpate +
J. Arnold Arbor. +
ebracteate;4-15-flowered +
ascending +  and erect +
slender +
not flexuous +
mucilaginous +
not +  and mucilaginous +
white +, black +, brown +  and yellow +
0.14 cm1.4 mm <br />0.0014 m <br /> (0.18 cm1.8 mm <br />0.0018 m <br />) +
0.08 cm0.8 mm <br />8.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
persistent +  and caducous +
distinct +
spreading +, ascending +  and erect +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
reduced +
latiseptate +, twisted +  and sessile +
indehiscent +  and dehiscent +
terete +, plane +, subglobose +, ovoid +, suborbicular +, linear +, oblong +, elliptic +, lanceolate +  and ovate +
latiseptate +, twisted +  and sessile +
indehiscent +  and dehiscent +
terete +, plane +, subglobose +, ovoid +, suborbicular +, linear +, oblong +, elliptic +, lanceolate +  and ovate +
Illustrated +  and Endemic +
tetradynamous +
1.3 cm13 mm <br />0.013 m <br /> (1.8 cm18 mm <br />0.018 m <br />) +
straight +
procumbent +  and decumbent +
prostrate +  and decumbent +
0.4 cm4 mm <br />0.004 m <br /> (1.3 cm13 mm <br />0.013 m <br />) +
subsessile +, sessile +  and petiolate +
0.17 cm1.7 mm <br />0.0017 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
persistent +
distinct +
0.1 cm1 mm <br />0.001 m <br /> (0.17 cm1.7 mm <br />0.0017 m <br />) +
pubescent +  and glabrous +
0.008 cm0.08 mm <br />8.0e-5 m <br /> (0.045 cm0.45 mm <br />4.5e-4 m <br />) +
Abdra +, Erophila +, Nesodraba +  and Tomostima +
Draba hitchcockii +
species +
short-stalked +, simple +  and stalked +
cruciform +  and forked +
0.006 cm0.06 mm <br />6.0e-5 m <br /> (0.05 cm0.5 mm <br />5.0e-4 m <br />) +
coiled +, 1-7-veined +  and veined +
anastomosing +
scapose +  and not +
pubescent +  and glabrous +
rhizomatous +, taprooted +, scapose +  and not +
perennial +, biennial +  and annual +
subshrub +  and herb +
aquatics +  and terrestrial +
glabrous +  and pubescent +