FNA: Draba alpina vs. Draba pilosa

	Draba alpina	Draba pilosa
	alpine Draba
Habit	Perennials; (cespitose); caudex branched (covered with persistent leaves or leaf remains); scapose.	Perennials; (not stoloniferous); caudex branched (covered with persistent, dry leaves and midveins); 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, 0.4–1.7 dm, glabrous or pubescent, trichomes simple, 0.2–0.9 mm, and fewer, 2–4-rayed, 0.1–0.6 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.	(imbricate); rosulate; petiolate; petiole (base thickened), ciliate throughout; blade linear to linear-oblanceolate, 0.5–1.5(–2.2) cm × 1–2.5(–4) mm, margins entire (thickened, ciliate, trichomes simple and 2-rayed, to 1.1 mm), surfaces pubescent, abaxially with simple trichomes, 0.3–1 mm, and 2–4-rayed ones, 0.1–0.5 mm, adaxially similar, or with only simple trichomes, (midvein prominent, thickened).
Cauline leaves	0.	0.
Racemes	6–18-flowered, ebracteate, considerably elongated in fruit; rachis not flexuous, pubescent as stem.	(2–)4–12-flowered, ebracteate, usually elongated in fruit; rachis not flexuous, glabrous or pubescent as stem.
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 ovate, 2–3.5 mm, pubescent, (trichomes simple and short-stalked, 2-rayed); petals pale to bright yellow, obovate, 3.5–6 × 2–3.5 mm; anthers ovate, 0.4–0.5 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, usually straight, rarely curved upward, 6–13 mm, glabrous or pubescent as stem.
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).	elliptic to lanceolate, 5–11 × 3–4 mm, plane, flattened; valves glabrous or puberulent with simple and short-stalked, 2-rayed trichomes, 0.07–0.3 mm; ovules 12–20 per ovary; style 0.4–0.9 mm (stigma about as wide as style).
Seeds	(pale brown), ovoid, 0.9–1.3 × 0.6–0.9 mm.	ovoid, 1.2–1.4 × 0.8–1 mm.
2n	= 80.

	Draba alpina	Draba pilosa
Phenology	Flowering Jun–Aug.	Flowering Jul–Aug.
Habitat	Moist tundra and ridges, sand and gravel flats or beaches	Dry gravelly slopes, sandy places, wet tundra
Elevation	0-1000 m (0-3300 ft)	0-1300 m (0-4300 ft)
Distribution	LB; MB; NU; ON; QC; Greenland; Europe (Finland, Norway, Russia, Sweden) [WildflowerSearch map] [BONAP county map]	AK; NT; NU; YT; e Asia (ne Russian Far East, n Siberia) [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.)	O. E. Schulz (1927) reduced Draba pilosa to a variety of the decaploid D. alpina and cited North American collections. The former species was not listed by C. L. Hitchcock (1941) or R. C. Rollins (1993). From D. alpina, D. pilosa is easily distinguished by having strongly thickened and persistent (versus not thickened) midveins and margins, and usually narrower leaf blades [1–2.5(–5) versus 2.5–6(–9) mm wide]. As recognized herein, Draba pilosa is broadly circumscribed to include perhaps two or three closely related taxa. All are scapose plants with large, yellow flowers and prominent, persistent midveins and petioles. Some Alaskan forms (e.g., Parker 7596, ALA), which grow in moist heath habitats, have leaves 3–5 mm wide, whereas the majority have narrower leaf blades rarely reaching 2.5 mm in width. Most plants assigned to this species have leaves with exclusively simple trichomes and often glabrous scapes. Others (e.g., Chesemore & Davies 13, Murray 3371, Parker & Batten 8954, all at ALA) have leaf blade surfaces and scapes with 2–4-rayed trichomes and blade margins ciliate with simple trichomes. One collection (Walker s.n., ALA) has a mixture of plants of both trichome types but no intermediates were found. Detailed molecular and cytological studies are needed on this complex to determine if more than one taxon is represented. (Discussion copyrighted by Flora of North America; reprinted with permission.)
Source	FNA vol. 7, p. 290.	FNA vol. 7, p. 330.
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. 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. alpina var. hydeana, D. alpina var. inflatisiliqua	D. alpina var. pilosa, D. aspera
Name authority	Linnaeus: Sp. Pl. 2: 642. (1753)	Adams ex de Candolle: in A. P. de Candolle, Syst. Nat. 2: 336. (1821)
Web links	WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search	WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search

Draba pilosa

alpine Draba

Habit

Perennials; (cespitose); caudex branched (covered with persistent leaves or leaf remains); scapose.

Perennials; (not stoloniferous); caudex branched (covered with persistent, dry leaves and midveins); 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, 0.4–1.7 dm, glabrous or pubescent, trichomes simple, 0.2–0.9 mm, and fewer, 2–4-rayed, 0.1–0.6 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.

(imbricate); rosulate; petiolate;

petiole (base thickened), ciliate throughout;

blade linear to linear-oblanceolate, 0.5–1.5(–2.2) cm × 1–2.5(–4) mm, margins entire (thickened, ciliate, trichomes simple and 2-rayed, to 1.1 mm), surfaces pubescent, abaxially with simple trichomes, 0.3–1 mm, and 2–4-rayed ones, 0.1–0.5 mm, adaxially similar, or with only simple trichomes, (midvein prominent, thickened).

Cauline leaves

Racemes

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

rachis not flexuous, pubescent as stem.

(2–)4–12-flowered, ebracteate, usually elongated in fruit;

rachis not flexuous, glabrous or pubescent as stem.

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 ovate, 2–3.5 mm, pubescent, (trichomes simple and short-stalked, 2-rayed);

petals pale to bright yellow, obovate, 3.5–6 × 2–3.5 mm;

anthers ovate, 0.4–0.5 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, usually straight, rarely curved upward, 6–13 mm, glabrous or pubescent as stem.

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).

elliptic to lanceolate, 5–11 × 3–4 mm, plane, flattened;

valves glabrous or puberulent with simple and short-stalked, 2-rayed trichomes, 0.07–0.3 mm;

ovules 12–20 per ovary;

style 0.4–0.9 mm (stigma about as wide as style).

Seeds

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

ovoid, 1.2–1.4 × 0.8–1 mm.

= 80.

Draba alpina

Draba pilosa

Phenology

Flowering Jun–Aug.

Flowering Jul–Aug.

Habitat

Moist tundra and ridges, sand and gravel flats or beaches

Dry gravelly slopes, sandy places, wet tundra

Elevation

0-1000 m (0-3300 ft)

0-1300 m (0-4300 ft)

Distribution

LB; MB; NU; ON; QC; Greenland; Europe (Finland, Norway, Russia, Sweden)

[WildflowerSearch map]

[BONAP county map]

AK; NT; NU; YT; e Asia (ne Russian Far East, n Siberia)

[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.)

O. E. Schulz (1927) reduced Draba pilosa to a variety of the decaploid D. alpina and cited North American collections. The former species was not listed by C. L. Hitchcock (1941) or R. C. Rollins (1993). From D. alpina, D. pilosa is easily distinguished by having strongly thickened and persistent (versus not thickened) midveins and margins, and usually narrower leaf blades [1–2.5(–5) versus 2.5–6(–9) mm wide].

As recognized herein, Draba pilosa is broadly circumscribed to include perhaps two or three closely related taxa. All are scapose plants with large, yellow flowers and prominent, persistent midveins and petioles. Some Alaskan forms (e.g., Parker 7596, ALA), which grow in moist heath habitats, have leaves 3–5 mm wide, whereas the majority have narrower leaf blades rarely reaching 2.5 mm in width. Most plants assigned to this species have leaves with exclusively simple trichomes and often glabrous scapes. Others (e.g., Chesemore & Davies 13, Murray 3371, Parker & Batten 8954, all at ALA) have leaf blade surfaces and scapes with 2–4-rayed trichomes and blade margins ciliate with simple trichomes. One collection (Walker s.n., ALA) has a mixture of plants of both trichome types but no intermediates were found. Detailed molecular and cytological studies are needed on this complex to determine if more than one taxon is represented.

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

Source

FNA vol. 7, p. 290.

FNA vol. 7, p. 330.

Parent taxa

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. 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. alpina var. hydeana, D. alpina var. inflatisiliqua

D. alpina var. pilosa, D. aspera

Name authority

Linnaeus: Sp. Pl. 2: 642. (1753)

Adams ex de Candolle: in A. P. de Candolle, Syst. Nat. 2: 336. (1821)

Web links

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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Draba alpina

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Draba alpina

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