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alpine whitlow-grass, golden alpine Draba, golden Draba, great alpine whitlow-grass, Mt. Lassen Draba, Mt. Lassen Draba whitlow-grass, Mt. Lassen whitlow-grass

Porsild's Draba, Porsild's whitlow-grass

Habit Perennials; (short-lived); caudex simple or branched (poorly developed, with persistent dry leaves); not scapose. Perennials; (cespitose); caudex branched (with persistent leaf remains); often scapose.
Stems

unbranched or branched, 0.3–1.5 dm, hirsute throughout, trichomes simple and long-stalked, 2–4-rayed, 0.2–1.5 mm.

unbranched, 0.2–1.2 dm, sparsely pubescent proximally, trichomes short-stalked, 3–5- rayed, (non-crisped), 0.2–0.4 mm, glabrous distally.

Basal leaves

(forming dense clusters); rosulate;

sessile;

blade oblanceolate to linear, (0.7–)1–2.5(–3.2) cm × 2–3.5(–5) mm, margins entire, (ciliate, trichomes simple and 2-rayed, 0.5–1.5 mm), surfaces densely hirsute, abaxially with stalked, 3–5-rayed trichomes, 0.1–0.5 mm, adaxially with simple and long-stalked, 2-rayed trichomes, to 1 mm, with smaller, 3–5-rayed ones.

rosulate;

subsessile or shortly petiolate;

petiole base and margin ciliate proximally, (trichomes simple, subsetiform, stiff, 0.3–0.9 mm);

blade oblanceolate to obovate, 0.4–1.5 cm × 1–3 mm, margins entire, surfaces pubescent, abaxially with stalked, 6–12-rayed, (non-crisped) trichomes, 0.2–0.5 mm, (midvein obscure), adaxially similar, or with simple trichomes on proximal 1/2.

Cauline leaves

5–33;

sessile;

blade oblong to linear, margins entire, surfaces pubescent as basal.

0 or 1;

sessile;

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

Racemes

12–83-flowered, ebracteate or proximalmost 1–9 flowers bracteate, slightly or not elongated in fruit;

rachis not flexuous, hirsute as stem.

3–13-flowered, ebracteate, elongated in fruit;

rachis not flexuous, glabrous.

Flowers

sepals ovate, 2.5–4 mm, glabrous;

petals bright yellow, linear to linear-oblanceolate, 4–6 × 0.5–1(–1.2) mm;

anthers narrowly oblong, 0.8–1 mm.

sepals ovate, 1.5–2 mm, pubescent, (trichomes simple and 2-rayed);

petals white, spatulate, 2–4 × 1–1.7 mm;

anthers ovate, ca. 0.2 mm.

Fruiting pedicels

horizontal to divaricate, usually straight, rarely curved upward, (3–)5–12(–19) mm, hirsute as stem.

divaricate-ascending, straight, 1–4(–8) mm, glabrous.

Fruits

oblong or, rarely, oblong-ovate, plane, flattened, (6–)9–14(–16) × 3–5 mm;

valves pubescent, trichomes stalked, 2–4-rayed, 0.07–0.5 mm;

ovules 10–20 per ovary;

style (0.6–)1–1.6(–2) mm.

ovate to oblong, plane, flattened, 4–7.5 × 1.7–3 mm;

valves glabrous;

ovules 12–16 per ovary;

style 0.1–0.3(–0.5) mm.

Seeds

oblong, 1.4–1.9 × 0.8–1.1 mm.

ovoid, 0.7–1 × 0.5–0.6 mm.

2n

= 20.

= 32.

Draba aureola

Draba porsildii

Phenology Flowering Jul–Aug. Flowering Jun–Jul.
Habitat Open conifer forests, alpine meadows and moraines, talus slopes Rock outcrops, talus, meadows, gravel slopes
Elevation 2200-3200 m (7200-10500 ft) 600-3000 m (2000-9800 ft)
Distribution
from FNA
CA; OR; WA
[WildflowerSearch map]
[BONAP county map]
from FNA
AK; MT; WY; AB; YT
[BONAP county map]
Discussion

Draba aureola is known from Lassen, Shasta, and Siskiyou counties in California, Deschutes County in Oregon, and Lewis and Pierce counties in Washington.

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

According to H. H. Grundt et al. (2004), tetraploid Draba porsildii probably originated from a diploid ancestor such as D. lonchocarpa. The Wyoming plants are a close match to the type of the species, though they have distinctly shorter pedicels. Some of the Alaskan plants are more problematic; they have finer and more branched trichomes, larger flowers, longer pedicels, and longer styles than the type. It is likely that they belong to another species; detailed molecular and cytological studies on this complex are needed before any meaningful conclusions are reached.

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

Source FNA vol. 7, p. 295. FNA vol. 7, p. 331.
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. 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. 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. aureola var. paniculata D. nivalis var. brevicula, D. porsildii var. brevicula
Name authority S. Watson: in W. H. Brewer et al., Bot. California 2: 430. (1880) G. A. Mulligan: Canad. J. Bot. 52: 1795, fig. 8. (1974)
Web links