Flora of North America species comparison

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Draba oligosperma

Draba norvegica

few-seed Draba, few-seed Draba whitlow-grass, few-seed whitlow-grass

Norwegian Draba
Habit Perennials; (cespitose, densely pulvinate); caudex branched (with persistent leaf bases, branches congested or somewhat creeping, sometimes terminating in sterile rosettes); scapose. Perennials; (cespitose); caudex branched (sometimes with persistent leaf remains); often scapose.
Stems

unbranched, (0.1–)0.2–0.6(–1) dm, glabrous throughout or pubescent, trichomes sessile, pectinate, 0.1–0.3 mm, (their length parallel to long axis of stem).

branched or unbranched, (0.2–)0.4–1.4(–2) dm, pubescent throughout, trichomes simple and 2–4-rayed, 0.2–0.5 mm.
Basal leaves

rosulate;

sessile;

blade linear to linear-oblanceolate, (0.2–)0.4–1.1(–1.5) cm × 0.4–1.5(–1.8) mm, margins entire, (not or, rarely, ciliate, trichomes simple, 0.2–0.4 mm), surfaces pubescent with sessile, pectinate trichomes, 0.1–0.4 mm, (their long axis parallel to prominent abaxial midvein), sometimes glabrous adaxially.

rosulate; petiolate;

petiole (0–0.5 cm), ciliate throughout;

blade oblanceolate to narrowly obovate or narrowly lanceolate, 0.4–2.1 cm × 1.5–7 mm, margins with 1–3 teeth on each side, (ciliate, trichomes simple and 2-rayed, 0.2–0.8 mm), surfaces pubescent abaxially with stalked, (2–)4(–6)-rayed trichomes, 0.1–0.4 mm, adaxially glabrous or pubescent, with simple and stalked, 2-rayed trichomes, 0.1–0.5 mm.
Cauline leaves

0.

0–3(–5);

sessile;

blade ovate to oblong, margins often dentate, (ciliate).
Racemes

4–12(–17)-flowered, ebracteate, elongated in fruit;

rachis not flexuous, glabrous or pubescent as stem.

5–23-flowered, ebracteate or proximalmost 1(–3) flowers bracteate, considerably elongated in fruit;

rachis slightly or not flexuous, pubescent as stem.
Flowers

sepals ovate, 1.5–3 mm, glabrous or sparsely pubescent, (trichomes pectinate, 2-rayed, or simple);

petals usually yellow, rarely creamy white, obovate, 2.5–4 × 1.5–3 mm;

anthers ovate, 0.4–0.5 mm, (not producing pollen).

sepals ovate, 1.7–2.5 mm, pubescent, (trichomes simple and short-stalked, 2–4-rayed);

petals white, spatulate, 2.5–4 × 1.7–2.5 mm;

anthers ovate, 0.3–0.4 mm.
Fruiting pedicels

divaricate-ascending, straight, (2–)3–10(–13) mm, glabrous or sparsely pubescent, trichomes pectinate.

suberect to ascending (often appressed to rachis), straight, (1.5–)2.5–5(–9) mm, pubescent, trichomes simple and 2–4-rayed.
Fruits

ovoid to lanceolate, plane, inflated at least basally, sometimes slightly flattened distally, 3–6(–7) × 2–3.5(–4) mm;

valves usually puberulent, rarely glabrous, trichomes simple and sessile, often unequally 2-rayed, 0.07–0.35 mm;

ovules 6–12 per ovary;

style 0.1–0.8(–1.1) mm.

(sometimes subappressed to rachis), oblong to lanceolate-elliptic, plane, flattened, 4–8 × 2–3 mm;

valves glabrous or pubescent, trichomes simple and short-stalked, 2-rayed, 0.05–0.25 mm;

ovules 18–26 per ovary;

style (0.01–)0.1–0.4(–0.5) mm, (glabrous, stigma about as wide as style).
Seeds

ovoid, 1.1–1.5 × 0.7–1 mm.

oblong, 0.9–1.2 × 0.5–0.7 mm.
2n

= 32, 64.

= 48.

Draba oligosperma

Draba norvegica
Phenology Flowering May–Jul. Flowering Jun–Aug.
Habitat Rock outcrops, talus, gravel benches, tundra Rock outcrops and sea cliffs, talus, gravelly and sandy terraces, moist bluffs, turfy limestone shores
Elevation 200-3900 m (700-12800 ft) 0-500 m (0-1600 ft)
Distribution
from FNA
AK; CA; CO; ID; MT; NV; OR; WY; AB; BC; NT; NU; YT
[WildflowerSearch map]
[BONAP county map]
from FNA
NL; NS; NT; QC; Greenland; Europe (Finland, Norway, n Russia, Scotland, Sweden); Atlantic Islands (Iceland)
[BONAP county map]
Discussion

Draba oligosperma is a highly variable and widespread species that has been shown to be apomictic (G. A. Mulligan and J. N. Findlay 1970; Mulligan 1972). It has been divided into species and infraspecific taxa by previous authors; the variation is continuous in every character; there are no clear geographical and morphological patterns that support its division. For characteristics separating D. oligosperma from the closely related D. pectinipila, see 80. D. pectinipila.

Draba andina (Nuttall) A. Nelson (1899), not Philippi (1858) is an illegitimate name, sometimes found in synonymy under D. oligosperma.

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

Draba norvegica is a highly variable hexaploid taxon and, as delimited herein, it probably represents two taxa with the same distribution and same chromosome number. It is related to hexaploid D. arctogena, from which it is distinguished by characteristics listed under 8. D. arctogena.

Draba norvegica was divided by O. E. Schulz (1927) into eight varieties, whereas R. C. Rollins (1993) recognized just two. In the latter treatment, var. clivicola is distinguished by having predominantly branched, appressed trichomes on stems proximally, lanceolate, glabrous fruits, and slender, erect-appressed pedicels. By contrast, var. norvegica is said to have predominantly simple, spreading trichomes on stems proximally, narrowly ovate to elliptical, glabrous or pubescent fruits, and stout, divaricately ascending pedicels. These differences are extremes of a continuum, and we agree with G. A. Mulligan (1970) in reducing D. clivicola to synonymy of D. norvegica. Rollins indicated that D. norvegica grows in Minnesota, but we have not seen any material from that state.

Draba norvegica is found in Europe in arctic and subarctic areas.

(Discussion copyrighted by Flora of North America; reprinted with permission.)
Source FNA vol. 7, p. 324. FNA vol. 7, p. 322.
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. 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. 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. 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. calcifuga, D. oligosperma var. andina, D. oligosperma var. leiocarpa, D. oligosperma var. microcarpa, D. oligosperma var. saximontana, D. oligosperma subsp. subsessilis, D. oligosperma var. subsessilis, D. saximontana, D. subsessilis D. clivicola, D. hirta var. norvegica, D. norvegica var. clivicola, D. norvegica var. hebecarpa, D. rupestris, D. scandinavica var. hebecarpa, D. trichella
Name authority Hooker: Fl. Bor.-Amer. 1: 51. (1830) Gunnerus: Fl. Norveg. 2: 106. (1772)
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Unless otherwise noted, all data comes from the online version of the Flora of North America, who have made most of their content available via a Creative Commons license (CC BY 4.0).



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