Draba brachystylis

Rydberg

Bull. Torrey Bot. Club 29: 240. 1902.

Treatment appears in FNA Volume 7. Treatment on page 297. Mentioned on page 273, 278, 335.

Annuals or perennials; (short-lived); caudex often simple (poorly developed); not scapose. Stems unbranched or branched, 0.6–3 (–3.7) dm, pubescent throughout, trichomes simple, 0.4–0.9 mm, and 2–4-rayed, 0.05–0.4 mm. Basal leaves rosulate; subsessile; petiole base ciliate, (trichomes simple, 0.3–0.9 mm); blade oblanceolate, 1–3.5 cm × 4–7 (–12) mm, margins entire or denticulate, surfaces pubescent, abaxially with stalked, (2–) 4-rayed trichomes, 0.1–0.5 mm, adaxially with simple trichomes, 0.2–0.6 mm, with smaller, 2–4-rayed ones. Cauline leaves (1 or) 2–6 (–8); sessile; blade lanceolate or oblanceolate to ovate, margins entire or denticulate, surfaces pubescent as basal. Racemes (5–) 10–35 (–47) -flowered, ebracteate, elongated in fruit; rachis not flexuous, pubescent as stem. Fruiting pedicels divaricate-ascending, straight or only slightly curved upward, (1.5–) 3–8 (–10) mm, pubescent throughout, trichomes simple and stalked, 2–4-rayed. Flowers: sepals ovate, 2–2.7 mm, pubescent, (trichomes simple and short-stalked, 2-rayed); petals pale-yellow (fading white), oblanceolate, 2.5–3.7 × 0.9–1.2 mm; anthers ovate, 0.2–0.3 mm. Fruits narrowly elliptic to lanceolate, plane, flattened, (7–) 10–16 (–19) × 2–3.5 mm; valves pubescent, trichomes simple, spurred, and short-stalked, 2-rayed, 0.05–0.2 (–0.3) mm; ovules 20–36 (–42) per ovary; style 0.2–0.6 (–0.8) mm. Seeds oblong, 0.9–1.3 × 0.6–0.7 mm. 2n = 44.


Phenology: Flowering Jun–Jul.
Habitat: Fir and aspen communities, moist areas on rocky slopes
Elevation: 1700-3000 m

Discussion

Of conservation concern.

Based on morphological and chromosomal data (L. Allphin and M. D. Windham, unpubl.), Draba brachystylis is hypothesized to be an allopolyploid derived through hybridization between D. albertina and D. santaquinensis. It is known to us only from Cache, Duchesne, Juab, Salt Lake, and Utah counties. C. L. Hitchcock (1941) indicated that the species grows in the Charleston Mountains of Clark County, Nevada, but we have not seen unequivocal material of it from that area.

Selected References

None.

Lower Taxa

None.

"elongated" is not a number."thick" is not a number."dm" is not declared as a valid unit of measurement for this property."dm" is not declared as a valid unit of measurement for this property.

... more about "Draba brachystylis"
0.02 cm0.2 mm <br />2.0e-4 m <br /> (0.03 cm0.3 mm <br />3.0e-4 m <br />) +
Ihsan A. Al-Shehbaz +, Michael D. Windham +  and Reidar Elven +
Rydberg +
appendaged +  and unappendaged +
0.7 cm7 mm <br />0.007 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
not +  and auriculate +
1 cm10 mm <br />0.01 m <br /> (3.5 cm35 mm <br />0.035 m <br />) +
lobed +, toothed +  and entire +
oblanceolate;ovate +
much smaller +  and reduced +
0.4 cm4 mm <br />0.004 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
urceolate +, campanulate +  and tubular +
not scapose +  and simple +
well-developed +
distinct +
well-differentiated +
emarginate +  and entire +
1700-3000 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 +
1.6 cm16 mm <br />0.016 m <br /> (1.9 cm19 mm <br />0.019 m <br />) +
indehiscent +  and dehiscent +
1 cm10 mm <br />0.01 m <br /> (1.6 cm16 mm <br />0.016 m <br />) +
flattened +, plane +, narrowly elliptic +  and lanceolate +
0.2 cm2 mm <br />0.002 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
Fir and aspen communities, moist areas on rocky slopes +
sessile +  and petiolate +
alternate +, not +  and rosulate +
cauline +  and basal +
connate +  and distinct +
decurrent +
dentate +  and entire +
denticulate;entire;denticulate;entire +
smaller +
tenuinucellate +, crassinucellate +  and bitegmic +
campylotropous +  and anatropous +
pale-yellow +
2.5mm;3.7mm +
rudimentary +
oblanceolate +
0.09 cm0.9 mm <br />9.0e-4 m <br /> (0.12 cm1.2 mm <br />0.0012 m <br />) +
Flowering Jun–Jul. +
trinucleate +  and 3(-11)-colpate +
Bull. Torrey Bot. Club +
ebracteate;(5-)10-35(-47)-flowered +
ascending +  and erect +
slender +
not flexuous +
mucilaginous +
not +  and mucilaginous +
white +, black +, brown +  and yellow +
0.09 cm0.9 mm <br />9.0e-4 m <br /> (0.13 cm1.3 mm <br />0.0013 m <br />) +
0.06 cm0.6 mm <br />6.0e-4 m <br /> (0.07 cm0.7 mm <br />7.0e-4 m <br />) +
persistent +  and caducous +
distinct +
spreading +, ascending +  and erect +
0.2 cm2 mm <br />0.002 m <br /> (0.27 cm2.7 mm <br />0.0027 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 +
tetradynamous +
branched +  and unbranched +
procumbent +  and decumbent +
prostrate +  and decumbent +
usually erect +  and ascending +
subsessile +, sessile +  and petiolate +
0.06 cm0.6 mm <br />6.0e-4 m <br /> (0.08 cm0.8 mm <br />8.0e-4 m <br />) +
persistent +
distinct +
0.02 cm0.2 mm <br />2.0e-4 m <br /> (0.06 cm0.6 mm <br />6.0e-4 m <br />) +
0.02 cm0.2 mm <br />2.0e-4 m <br /> (0.06 cm0.6 mm <br />6.0e-4 m <br />) +
Abdra +, Erophila +, Nesodraba +  and Tomostima +
Draba brachystylis +
species +
short-stalked +, simple +  and stalked +
0.02 cm0.2 mm <br />2.0e-4 m <br /> (0.03 cm0.3 mm <br />3.0e-4 m <br />) +
cruciform +  and forked +
0.005 cm0.05 mm <br />5.0e-5 m <br /> (0.02 cm0.2 mm <br />2.0e-4 m <br />) +
coiled +, 1-7-veined +  and veined +
anastomosing +
scapose +  and not +
0.8 cm8 mm <br />0.008 m <br /> (1 cm10 mm <br />0.01 m <br />) +
curved +  and straight +
perennial +  and annual +
divaricate-ascending +
0.3 cm3 mm <br />0.003 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
rhizomatous +, taprooted +, scapose +  and not +
perennial +, biennial +  and annual +
subshrub +  and herb +
aquatics +  and terrestrial +
glabrous +  and pubescent +