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arctic Draba, Austrian Draba, Austrian whitlow-grass

Habit Perennials; (sometimes cespitose); caudex simple or branched (with persistent leaf bases); usually scapose. Perennials; (cespitose); caudex branched (covered with persistent petiole remains); scapose.
Stems

unbranched, (0.2–)0.3–1(–1.3) dm, glabrous.

unbranched, 0.2–1.1 dm, pubescent proximally, trichomes short-stalked, 2–5-rayed, 0.1–0.5 mm, (some rays spurred).

Basal leaves

rosulate;

petiole (obscure), margin ciliate, (trichomes simple or 2-rayed, 0.25–0.6 mm);

blade linear to oblanceolate or narrowly obovate, (0.3–)0.4–1.2(–1.6) cm × 1–3(–4) mm, margins usually entire, rarely toothed, surfaces abaxially pubescent or glabrous, trichomes simple, sometimes with fewer, short-stalked, 2-rayed ones, (midvein prominent), adaxially often glabrous.

rosulate;

petiolate;

petiole base and margin ciliate, (trichomes simple, 0.3–1 mm);

blade oblanceolate to lanceolate, 0.8–2.2 cm × 2–6 mm, margins often entire, surfaces pubescent abaxially with stalked, 2–5-rayed, stellate trichomes, 0.1–0.4 mm, often some rays spurred and trichomes appearing subdendritic, rarely glabrate, or with simple and 2-rayed ones, (midvein obscure abaxially, not thickened), adaxially glabrous or sparsely pubescent with simple trichomes, sometimes with long-stalked, 2- or 3-rayed ones.

Cauline leaves

0–2;

sessile;

blade oblong to ovate, margins entire, (ciliate).

0.

Racemes

(2 or) 3–11(–14)-flowered, usually ebracteate, rarely proximalmost flowers bracteate, elongated in fruit;

rachis not flexuous, glabrous.

(2–)4–13-flowered, ebracteate, (subcorymbose), not elongated in fruit;

rachis not flexuous, pubescent as stem.

Flowers

sepals (green or purplish), ovate, 1.2–2.2 mm, glabrous or pubescent, (trichomes simple);

petals white, spatulate, 2–2.5 × 0.8–1.5 mm;

anthers ovate, 0.2–0.25 mm.

sepals (grayish white), ovate to broadly so, 2.5–3 mm, pubescent, (trichomes simple and stalked, 2-rayed);

petals creamy white to yellow, broadly obovate, 3.5–5 × 2.5–3.5 mm;

anthers ovate, 0.4–0.5 mm.

Fruiting pedicels

divaricate-ascending, often straight, (1–)2–5(–6) mm, glabrous.

subhorizontal to divaricate-ascending (not appressed to rachis), often slightly curved upward, 4–7(–10) mm, pubescent, trichomes simple (0.4–1 mm), and 2–4-rayed (0.1–0.4 mm).

Fruits

elliptic-lanceolate to oblong, plane, flattened, 3–8(–9) × 1.5–2 mm;

valves glabrous;

ovules 12–24 per ovary;

style 0.05–0.2(–0.3) mm.

ovate to ovate-oblong, plane, flattened, 5–10 × 3–5 mm;

valves puberulent along replum, trichomes simple, 0.1–0.3 mm;

ovules (16–)18–28 per ovary;

style 0.2–0.6 mm (stigma as wide as style).

Seeds

oblong to elliptic, 0.8–1 × 0.5–0.6 mm.

(black), ovoid, 1–1.3 × 0.6–0.8 mm.

2n

= 16.

= 64.

Draba fladnizensis

Draba oxycarpa

Phenology Flowering Jun–Aug. Flowering Jun–Jul.
Habitat Rock outcrops and talus, alpine meadows, sandy gravel Rocky soils
Elevation 0-1400 m at higher latitudes, 3000-3800 m at lower latitudes (0-4600 ft at higher latitudes, 9800-12500 ft at lower latitudes)
Distribution
from FNA
AK; CO; UT; WY; BC; NT; NU; QC; YT; Greenland; c Europe; s Europe; Asia; circumpolar and high alpine areas
[WildflowerSearch map]
[BONAP county map]
Greenland; Europe (Norway [including Spitsbergen], Sweden); Atlantic Islands (Iceland)
[BONAP county map]
Discussion

Rollins reduced Draba pattersonii to a variety of D. fladnizensis and separated the two primarily on plant size and minor differences in fruit shape. Examination of D. fladnizensis specimens collected throughout Europe and North America reveals that the alleged differences between the two taxa are artificial. The type material of D. pattersonii, which was collected in Colorado, is a mixture of plants highly variable in their type of indumentum. The specimens have no flowers, but the habit, fruits, and leaves are nearly indistinguishable from those of D. fladnizensis from higher latitudes.

In the absence of flowers, the white-flowered Draba fladnizensis (2n = 16) is often confused with the yellow-flowered D. crassifolia (2n = 40). The latter is an annual or short-lived perennial that rarely forms a well-developed caudex, whereas D. fladnizensis almost always produces a distinct caudex. Although most individuals of both species are scapose, they occasionally produce one or two cauline leaves. The cauline leaves are usually glabrous in D. crassifolia and ciliate in D. fladnizensis; in the latter, the distalmost cauline leaf usually subtends the proximalmost flower. Finally, the seeds in D. fladnizensis are slightly larger (0.8–0.1 × 0.5–0.6 versus 0.7–0.8 × 0.4–0.5 mm) than those of D. crassifolia, though the reliability of this distinction needs to be examined in greater detail. N. H. Holmgren (2005b) reported D. fladnizensis from central Nevada, but we have not seen any material of the species from that state.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Draba oxycarpa is an octoploid that most closely resembles the decaploid D. alpina. It is distinguished from that species by having creamy white to pale yellow (versus bright yellow) petals, gray-green (versus purplish tinged) sepals, petals 2.5–3.5 (versus 1.7–2.5) mm wide, stems pubescent proximally with primarily branched (versus primarily simple) trichomes, nearly black (versus pale brown) seeds, and ovate to ovate-oblong (versus elliptic) fruits 3–5 (versus 2–3) mm wide.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 7, p. 307. FNA vol. 7, p. 325.
Parent taxa Brassicaceae > tribe Arabideae > Draba Brassicaceae > tribe Arabideae > Draba
Sibling taxa
D. abajoensis, D. albertina, D. aleutica, D. alpina, D. aprica, D. arabisans, D. arctica, D. arctogena, D. argyrea, D. arida, D. asprella, D. asterophora, D. aurea, D. aureola, D. bifurcata, D. borealis, D. brachycarpa, D. brachystylis, D. breweri, D. burkei, D. californica, D. cana, D. carnosula, D. chamissonis, D. cinerea, D. corrugata, D. corymbosa, D. crassa, D. crassifolia, D. cruciata, D. cuneifolia, D. cusickii, D. cyclomorpha, D. daviesiae, D. densifolia, D. exunguiculata, D. glabella, D. globosa, D. graminea, D. grandis, D. grayana, D. heilii, D. helleriana, D. hitchcockii, D. howellii, D. incana, D. incerta, D. incrassata, D. inexpectata, D. jaegeri, D. juvenilis, D. kassii, D. kluanei, D. lactea, D. lemmonii, D. lonchocarpa, D. longisquamosa, D. macounii, D. maguirei, D. malpighiacea, D. micropetala, D. mogollonica, D. monoensis, D. mulliganii, D. murrayi, D. nemorosa, D. nivalis, D. norvegica, D. novolympica, D. oblongata, D. ogilviensis, D. oligosperma, D. oreibata, D. oxycarpa, D. palanderiana, D. pauciflora, D. paucifructa, D. paysonii, D. pectinipila, D. pedicellata, D. pennellii, D. petrophila, D. pilosa, D. platycarpa, D. porsildii, D. praealta, D. pterosperma, D. ramosissima, D. ramulosa, D. rectifructa, D. reptans, D. ruaxes, D. santaquinensis, D. saxosa, D. scotteri, D. serpentina, D. sharsmithii, D. sibirica, D. sierrae, D. simmonsii, D. smithii, D. sobolifera, D. spectabilis, D. sphaerocarpa, D. sphaeroides, D. standleyi, D. stenoloba, D. stenopetala, D. streptobrachia, D. streptocarpa, D. subalpina, D. subcapitata, D. subumbellata, D. trichocarpa, D. ventosa, D. verna, D. viridis, D. weberi, D. yukonensis, D. zionensis
D. abajoensis, D. albertina, D. aleutica, D. alpina, D. aprica, D. arabisans, D. arctica, D. arctogena, D. argyrea, D. arida, D. asprella, D. asterophora, D. aurea, D. aureola, D. bifurcata, D. borealis, D. brachycarpa, D. brachystylis, D. breweri, D. burkei, D. californica, D. cana, D. carnosula, D. chamissonis, D. cinerea, D. corrugata, D. corymbosa, D. crassa, D. crassifolia, D. cruciata, D. cuneifolia, D. cusickii, D. cyclomorpha, D. daviesiae, D. densifolia, D. exunguiculata, D. fladnizensis, D. glabella, D. globosa, D. graminea, D. grandis, D. grayana, D. heilii, D. helleriana, D. hitchcockii, D. howellii, D. incana, D. incerta, D. incrassata, D. inexpectata, D. jaegeri, D. juvenilis, D. kassii, D. kluanei, D. lactea, D. lemmonii, D. lonchocarpa, D. longisquamosa, D. macounii, D. maguirei, D. malpighiacea, D. micropetala, D. mogollonica, D. monoensis, D. mulliganii, D. murrayi, D. nemorosa, D. nivalis, D. norvegica, D. novolympica, D. oblongata, D. ogilviensis, D. oligosperma, D. oreibata, D. palanderiana, D. pauciflora, D. paucifructa, D. paysonii, D. pectinipila, D. pedicellata, D. pennellii, D. petrophila, D. pilosa, D. platycarpa, D. porsildii, D. praealta, D. pterosperma, D. ramosissima, D. ramulosa, D. rectifructa, D. reptans, D. ruaxes, D. santaquinensis, D. saxosa, D. scotteri, D. serpentina, D. sharsmithii, D. sibirica, D. sierrae, D. simmonsii, D. smithii, D. sobolifera, D. spectabilis, D. sphaerocarpa, D. sphaeroides, D. standleyi, D. stenoloba, D. stenopetala, D. streptobrachia, D. streptocarpa, D. subalpina, D. subcapitata, D. subumbellata, D. trichocarpa, D. ventosa, D. verna, D. viridis, D. weberi, D. yukonensis, D. zionensis
Synonyms D. fladnizensis var. pattersonii, D. pattersonii, D. pattersonii var. hirticaulis, D. wahlenbergii D. alpina var. oxycarpa, D. gredinii
Name authority Wulfen: in N. J. Jacquin, Misc. Austriac. 1: 147, plate 17, fig. 1. (1778) Sommerfelt: Mag. Naturvidensk., n. s. 1: 240. (1833)
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