The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

alpine Draba

subalpine Draba

Habit Perennials; (cespitose); caudex branched (covered with persistent leaves or leaf remains); scapose. Perennials; (cespitose); caudex simple or branched (with some persistent leaf bases); scapose.
Stems

unbranched, (0.3–)0.5–1.7(–2.8) dm, pubescent throughout, trichomes simple and 2-rayed, 0.3–0.8 mm, with 3–5-rayed ones, 0.1–0.3 mm.

unbranched, 0.3–1(–1.3) dm, often glabrous throughout, sometimes sparsely pubescent proximally, trichomes simple and stalked, 2-rayed, 0.2–1 mm.

Basal leaves

rosulate; petiolate;

petiole base (not thickened), ciliate, (trichomes simple, 0.3–1 mm);

blade oblanceolate to obovate or lanceolate to oblong, 0.8–3(–4.5) cm × 2.5–6(–9) mm, margins entire, surfaces abaxially pubescent with stalked, 2–4-rayed trichomes, 0.1–0.5 mm, with simple ones (midvein obscure, not thickened), adaxially glabrous or sparsely pubescent with simple and stalked, 2–4-rayed trichomes.

rosulate;

sessile;

blade (fleshy), oblanceolate to linear, (0.4–)0.5–1.4(–2) cm × (1–)1.5–3(–4) mm, margins entire, (ciliate at least apically, trichomes simple and 2-rayed), surfaces usually glabrous, rarely sparsely pubescent with simple and stalked, 2- (or 3-)rayed trichomes, 0.2–1 mm, (midvein obscure).

Cauline leaves

0.

0.

Racemes

6–18-flowered, ebracteate, considerably elongated in fruit;

rachis not flexuous, pubescent as stem.

(6–)10–28(–40)-flowered, ebracteate, elongated in fruit;

rachis not flexuous, glabrous.

Flowers

sepals (purplish tinged), narrowly ovate, 2.5–3 mm, pubescent, (trichomes simple and fewer, stalked, 2-rayed);

petals bright yellow, narrowly obovate, 3.5–5 × 1.7–2.5 mm;

anthers ovate, 0.3–0.4 mm.

sepals broadly ovate, 1.7–2.5 mm, usually glabrous, rarely pubescent, (trichomes simple and short-stalked, 2-rayed);

petals white, spatulate to obovate, 3–5 × 2–3 mm;

anthers oblong, 0.5–0.7 mm.

Fruiting pedicels

ascending to divaricate-ascending, straight or, sometimes, slightly curved upwards, 4–14(–30) mm, pubescent, trichomes simple and 2–4-rayed.

divaricate-ascending, straight, (3–)5–10(–17) mm, glabrous.

Fruits

elliptic, plane, flattened, 6–10 × 2–3 mm;

valves glabrous or glabrescent, trichomes simple, (not confined to replum);

ovules 12–24 per ovary;

style 0.2–0.3 mm (stigma about as wide as style).

ovoid to lanceolate, plane, inflated at least basally, 4–8(–10) × 2.5–4 mm;

valves glabrous or sparsely puberulent, trichomes simple, 0.02–0.1 mm;

ovules 6–12 per ovary;

style 0.2–0.9 mm.

Seeds

(pale brown), ovoid, 0.9–1.3 × 0.6–0.9 mm.

ovoid, 1–1.5 × 0.7–1.1 mm.

2n

= 80.

= 26.

Draba alpina

Draba subalpina

Phenology Flowering Jun–Aug. Flowering May–Jun.
Habitat Moist tundra and ridges, sand and gravel flats or beaches Rocky knolls and marly limestone soil in pine-oak-juniper woodlands, edges of spruce-fir forests
Elevation 0-1000 m (0-3300 ft) 1800-3400 m (5900-11200 ft)
Distribution
from FNA
LB; MB; NU; ON; QC; Greenland; Europe (Finland, Norway, Russia, Sweden)
[WildflowerSearch map]
[BONAP county map]
from FNA
UT
[WildflowerSearch map]
[BONAP county map]
Discussion

The synonymy above includes two North American names overlooked by C. L. Hitchcock (1941) and R. C. Rollins (1993). Draba alpina was broadly delimited by O. E. Schulz (1927) and included 17 varieties, some of which (e.g., corymbosa, oxycarpa, pilosa) are recognized herein as distinct species. The name D. alpina was so misapplied that it was used for any circumpolar or alpine, scapose, yellow-flowered, perennial Draba. Various chromosome numbers (e.g., 2n = 64, 80, 112, 120; S. I. Warwick and I. A. Al-Shehbaz 2006) have been reported for the species. As circumscribed here, it has the narrow distribution outlined above and includes plants with 2n = 80. Reports of the species from Alaska, Canadian Northwest Territories and Yukon, Siberia, eastern Asia, Russian Far East, and the Central Asian republics are either suspect or very unlikely. The entire D. alpina complex (including the above three species, D. glacialis Adams, D. macounii, etc.) is in need of critical molecular, cytological, and morphological study.

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

Molecular studies (M. A. Beilstein and M. D. Windham 2003) and chromosomal data (Windham 2000, 2004) suggest that Draba subalpina is most closely related to D. cusickii and D. sobolifera. From those, it is easily distinguished by having white (versus yellow) petals, glabrous (versus pubescent) rachises and stems distally, and glabrous or, rarely, sparsely pubescent (versus always pubescent) abaxial leaf blade surfaces. Draba subalpina is known from Garfield, Iron, Kane, and Wayne counties in south-central Utah.

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

Source FNA vol. 7, p. 290. FNA vol. 7, p. 342.
Parent taxa Brassicaceae > tribe Arabideae > Draba Brassicaceae > tribe Arabideae > Draba
Sibling taxa
D. abajoensis, D. albertina, D. aleutica, 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. 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. 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. subcapitata, D. subumbellata, D. trichocarpa, D. ventosa, D. verna, D. viridis, D. weberi, D. yukonensis, D. zionensis
Synonyms D. alpina var. hydeana, D. alpina var. inflatisiliqua
Name authority Linnaeus: Sp. Pl. 2: 642. (1753) Goodman & C. L. Hitchcock: Ann. Missouri Bot. Gard. 19: 77. (1932)
Web links