Draba corymbosa

R. Brown ex de Candolle

Syst. Nat. 2: 343. 1821.

Synonyms: Draba alpina var. bellii (Holm) O. E. Schulz Draba alpina var. corymbosa Durand Draba barbata Holm Draba bellii Lid ex E. Ekman Draba kjellmanii Adams Draba macrocarpa Davidson Draba vestita
Treatment appears in FNA Volume 7. Treatment on page 301. Mentioned on page 270, 287, 290, 302.

Perennials; (cespitose); caudex branched (with persistent leaves or leaf remains, branches sometimes terminating in sterile rosettes); scapose. Stems unbranched, (0.05–) 0.2–0.8 (–1.5) dm, pubescent throughout, trichomes simple and 2-rayed, 0.4–1 mm, with 3–5-rayed ones, 0.05–0.4 mm, (sometimes trichomes mostly simple). Basal leaves rosulate; petiolate; petiole base and margin ciliate, (trichomes often course, simple, 0.4–1.3 mm); blade oblanceolate to obovate, 0.6–1.8 cm × 1.5–5 mm, margins entire, surfaces pubescent, abaxially with stalked, 2–6-rayed trichomes, 0.2–0.6 mm, adaxially with primarily simple and stalked, 2-rayed trichomes, to 1.1 mm, with 3–5-rayed ones, 0.2–0.4 mm. Cauline leaves 0. Racemes 2–9 (–12) -flowered, ebracteate, (corymbose), slightly elongated in fruit; rachis not flexuous, pubescent as stem. Fruiting pedicels divaricate-ascending, straight or slightly curved upward, 4–11 (–16) mm, pubescent, trichomes simple and 2–4-rayed. Flowers: sepals (grayish green), broadly ovate, 2.2–3 mm, pubescent, (trichomes simple, to 1 mm, sometimes with stalked, smaller, 2–4-rayed ones); petals (broadly patent), yellow, obovate, 4–6 × 3–5 mm; anthers ovate, 0.3–0.4 mm. Fruits oblong or ovate, plane, flattened, 6–12 × 3.5–5.5 mm; valves pubescent or puberulent, trichomes simple, 0.1–0.4 mm, (sometimes with short-stalked, 2-rayed or 3-rayed ones); ovules 12–24 per ovary; style 0.6–1 mm (stigma distinctly wider than style). Seeds (brown), ovoid, 1–1.3 × 0.6–0.9 mm. 2n = 128, 144.


Phenology: Flowering Jun–Aug.
Habitat: Moist tundra, among calcareous or dolomitic rocks, gravel beaches, silt and clay terraces
Elevation: 0-1700 m

Distribution

V7 390-distribution-map.gif

Greenland, B.C., N.W.T., Nunavut, Yukon, Alaska, Europe (Norway), Europe (n Russia), e Asia (Russian Far East), e Asia (Siberia)

Discussion

Draba corymbosa, which is 16-ploid or 18-ploid with x = 8, is an extremely variable species of polyphyletic, allopolyploid origin. Most individuals appear to have decaploid D. alpina (2n = 80) in their parentage, but the other genomes are provided by hexaploid (2n = 48) and octoploid (2n = 64) species (C. Brochmann et al. 1993). O. E. Schulz reduced D. corymbosa to a variety of D. alpina; R. C. Rollins (1993) treated it as a distinct species. Draba corymbosa is distinguished from D. alpina by having pubescent or puberulent (versus glabrous or glabrescent) fruits, corymbose (versus usually elongated) fruiting racemes, and abaxial leaf blade surfaces always lacking (versus usually with some) simple trichomes.

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 corymbosa"
144 +  and 128 +
0.03 cm0.3 mm <br />3.0e-4 m <br /> (0.04 cm0.4 mm <br />4.0e-4 m <br />) +
Ihsan A. Al-Shehbaz +, Michael D. Windham +  and Reidar Elven +
R. Brown ex de Candolle +
appendaged +  and unappendaged +
not +  and auriculate +
0.6 cm6 mm <br />0.006 m <br /> (1.8 cm18 mm <br />0.018 m <br />) +
lobed +, toothed +  and entire +
oblanceolate;obovate +
much smaller +  and reduced +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
urceolate +, campanulate +  and tubular +
scapose +  and branched +
sessile +  and petiolate +
well-developed +
distinct +
well-differentiated +
emarginate +  and entire +
Greenland +, B.C. +, N.W.T. +, Nunavut +, Yukon +, Alaska +, Europe (Norway) +, Europe (n Russia) +, e Asia (Russian Far East) +  and e Asia (Siberia) +
0-1700 m +
straight +  and curved +
not winged +  and unappendaged +
connate +  and distinct +
not basally +  and dilated +
actinomorphic +
0.4 cm4 mm <br />0.004 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
spreading +, ascending +  and erect +
obovate +  and ovate +
0.22 cm2.2 mm <br />0.0022 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
0.3 cm3 mm <br />0.003 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
latiseptate +, twisted +  and sessile +
indehiscent +  and dehiscent +
0.6 cm6 mm <br />0.006 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
flattened +, plane +, ovate +  and oblong +
0.35 cm3.5 mm <br />0.0035 m <br /> (0.55 cm5.5 mm <br />0.0055 m <br />) +
Moist tundra, among calcareous or dolomitic rocks, gravel beaches, silt and clay terraces +
sessile +  and petiolate +
alternate +, not +  and rosulate +
cauline +  and basal +
connate +  and distinct +
decurrent +
pinnatifid +
tenuinucellate +, crassinucellate +  and bitegmic +
campylotropous +  and anatropous +
purple +, pink +, orange +, yellow +  and white +
rudimentary +
cruciform +
Flowering Jun–Aug. +
trinucleate +  and 3(-11)-colpate +
ebracteate;2-9(-12)-flowered +
ascending +  and erect +
slender +
not flexuous +
mucilaginous +
not +  and mucilaginous +
white +, black +, brown +  and yellow +
0.1 cm1 mm <br />0.001 m <br /> (0.13 cm1.3 mm <br />0.0013 m <br />) +
0.06 cm0.6 mm <br />6.0e-4 m <br /> (0.09 cm0.9 mm <br />9.0e-4 m <br />) +
persistent +  and caducous +
distinct +
spreading +, ascending +  and erect +
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 +
procumbent +  and decumbent +
prostrate +  and decumbent +
usually erect +  and ascending +
subsessile +, sessile +  and petiolate +
persistent +
distinct +
0.06 cm0.6 mm <br />6.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
0.02 cm0.2 mm <br />2.0e-4 m <br /> (0.04 cm0.4 mm <br />4.0e-4 m <br />) +
Draba alpina var. bellii +, Draba alpina var. corymbosa +, Draba barbata +, Draba bellii +, Draba kjellmanii +, Draba macrocarpa +  and Draba vestita +
Draba corymbosa +
species +
simple +  and stalked +
cruciform +  and forked +
0.01 cm0.1 mm <br />1.0e-4 m <br /> (0.04 cm0.4 mm <br />4.0e-4 m <br />) +
coiled +, 1-7-veined +  and veined +
puberulent +  and pubescent +
anastomosing +
scapose +  and not +
1.1 cm11 mm <br />0.011 m <br /> (1.6 cm16 mm <br />0.016 m <br />) +
curved +  and straight +
divaricate-ascending +
0.4 cm4 mm <br />0.004 m <br /> (1.1 cm11 mm <br />0.011 m <br />) +
rhizomatous +, taprooted +, scapose +  and not +
perennial +, biennial +  and annual +
subshrub +  and herb +
aquatics +  and terrestrial +
glabrous +  and pubescent +