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beavertip Draba, rockcress Draba, round-fruit Draba

arctic whitlowgrass

Habit Perennials; (cespitose, pulvinate); caudex branched (with persistent leaves, branches sometimes terminating in sterile rosettes); scapose. Perennials; (cespitose, not pulvinate); caudex simple or branched; rarely scapose.
Stems

unbranched, 0.1–0.5 dm, glabrous.

unbranched, 0.3–1.7(–2.4) dm, pubescent, trichomes 4–10-rayed (rays sometimes branched), 0.1–0.3 mm, with fewer, simple ones, to 0.7 mm.

Basal leaves

rosulate;

sessile;

blade (not fleshy), narrowly oblanceolate or lanceolate to linear, (0.2–)0.3–0.8 cm × 0.5–1.6(–2) mm, margins entire (ciliate, trichomes simple, 0.1–0.8 mm, apex acute, trichomes usually longer), surfaces glabrous, (midvein obscure abaxially).

rosulate; petiolate;

petiole base ciliate, (trichomes simple, 0.2–0.8 mm);

blade oblanceolate to narrowly obovate, 0.4–2.3(–3) cm × 1.5–6.5 mm, margins usually entire, rarely with 1 tooth on each side, surfaces densely pubescent with minutely stalked, 8–12-rayed, stellate trichomes, 0.2–0.4 mm, sometimes with coarser, simple or 2-rayed ones, (midvein distinct abaxially).

Cauline leaves

0.

0 or 1(–3);

sessile;

blade ovate or oblong to lanceolate, margins entire, surfaces pubescent as basal.

Racemes

2–5(–7)-flowered, ebracteate, slightly elongated in fruit;

rachis not flexuous, glabrous.

3–18(–25)-flowered, ebracteate, elongated in fruit;

rachis not flexuous, pubescent as stem.

Flowers

sepals (persistent to near fruit maturity), ovate to broadly oblong, 2–3 mm, glabrous;

petals white to pale yellow, obovate, 2.5–4 × 1.2–2 mm;

anthers oblong, 0.4–0.6 mm.

sepals ovate, 2–2.5 mm, pubescent, (trichomes short-stalked, 2- or 3-rayed, and simple);

petals white, spatulate to obovate, 3.5–6 × 1.8–2 mm;

anthers ovate, 0.3–0.4 mm.

Fruiting pedicels

divaricate-ascending, straight or slightly curved, 2–6 mm, glabrous.

divaricate-ascending or ascending, straight, (1.5–)2–6 mm, pubescent, trichomes stalked, stellate, and, sometimes, simple.

Fruits

ovate, plane, flattened, 4.5–8 × 2.5–4 mm;

valves (distinctly veined), glabrous;

ovules 8–16 per ovary;

style (0.1–)0.2–0.6 mm.

oblong to lanceolate, plane, slightly flattened, (5–)6–11 × 2–3 mm;

valves pubescent, trichomes short-stalked, 2–5-rayed (some rays branched), 0.05–0.3 mm;

ovules 20–32 per ovary;

style 0.1–1 mm (stigma distinctly wider than style).

Seeds

oblong, 1.1–1.4 × 0.8–1 mm.

ovoid, 0.8–1.1 × (0.6–)0.7–0.8 mm.

2n

= 80.

Draba globosa

Draba arctica

Phenology Flowering Jun–Aug. Flowering Jun–Jul.
Habitat Ridges, talus, alpine tundra and meadows Clay flats, gravel, beaches, limestone outcrops, talus
Elevation 2700-3900 m (8900-12800 ft) 0-500 m (0-1600 ft)
Distribution
from FNA
ID; MT; UT; WY
[WildflowerSearch map]
[BONAP county map]
from FNA
NU; Greenland; Europe (Norway [Svalbard])
[BONAP county map]
Discussion

Draba globosa is an apomictic species closely related to D. burkei (M. D. Windham, unpubl.). Though often treated as a variety of D. densifolia, it is morphologically and phyletically distinct from that species. Both R. C. Rollins (1993) and N. H. Holmgren (2005b) indicated that the species occurs in Colorado, but we have not seen material for that state.

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

As circumscribed here, Draba arctica consists of two distinct elements often recognized as subspecies (arctica and ostenfeldii; T. W. Böcher 1966); perhaps they are better treated as distinct species (D. arctica and D. ovibovina). Lack of adequate material and inability to examine all of the types in this complex prevent us from doing so.

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

Source FNA vol. 7, p. 308. FNA vol. 7, p. 291.
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. fladnizensis, D. glabella, 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. 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. 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
Synonyms D. apiculata, D. densifolia var. apiculata, D. densifolia var. decipiens, D. densifolia var. globosa D. arctica subsp. ostenfeldii, D. arctica var. ostenfeldii, D. cinerea var. arctica, D. ostenfeldii, D. ostenfeldii var. ovibovina, D. ovibovina
Name authority Payson: Amer. J. Bot. 4: 257. (1917) J. Vahl: in G. C. Oeder et al., Fl. Dan. 13(39): plate 5, 2294. (1840)
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