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Alaska Draba, Alaska whitlow-grass

bitter root Draba

Habit Biennials or perennials; (short-lived, not cespitose); caudex simple (not fleshy); scapose. Perennials; (densely pulvinate); caudex branched (branches elongated, loose, with persistent leaf remains, terminating in flowering or sterile shoots); scapose.
Stems

often unbranched, (0.2–)0.4–3(–3.4) dm, pubescent proximally, usually glabrous distally, rarely sparsely pubescent, trichomes short-stalked, 2–4-rayed, 0.1–0.4(–0.5) mm.

unbranched, (0.05–)0.2–0.6 dm, glabrous.

Basal leaves

rosulate;

petiole (obscure), margin ciliate, (trichomes simple, 0.2–0.4 mm);

blade oblanceolate to obovate, 0.4–2.6(–3.1) cm × 1.5–7(–10) mm, margins entire or denticulate, (ciliate as petiole), surfaces pubescent, abaxially with short-stalked, 3- or 4-rayed trichomes, 0.1–0.5 mm, adaxially with simple and stalked, 2–4-rayed trichomes, 0.1–0.5 mm.

(densely imbricate); rosulate; petiolate;

petiole ciliate throughout;

blade (fleshy), oblong to obovate or oblanceolate, 0.3–0.7(–1) cm × 1–2(–2.5) mm, margins entire, (ciliate, trichomes simple, 0.1–0.5 mm, apex obtuse), surfaces glabrous (midvein obscure abaxially).

Cauline leaves

(0 or) 1 or 2 (3 or 4);

sessile;

blade elliptic to lanceolate or ovate, margins toothed, surfaces pubescent, abaxially with short-stalked 3- or 4-rayed trichomes, adaxially with simple and short-stalked, 2–4-rayed trichomes.

0.

Racemes

(2–)4–10(–15)-flowered, ebracteate, elongated in fruit;

rachis not flexuous, usually glabrous, rarely sparsely pubescent.

2–8(–10)-flowered, ebracteate, (subcorymbose), slightly elongated in fruit;

rachis not flexuous, glabrous.

Flowers

(chasmogamous, petaliferous);

sepals (green or purplish), oblong, 1.5–2.5 mm, glabrous or pubescent, (trichomes simple);

petals yellow, oblanceolate, 2.5–3.5 × 0.6–1 mm;

anthers ovate, 0.25–0.4 mm.

sepals oblong, 1.5–2.2 mm, glabrous;

petals pale to bright yellow, spatulate, 3.5–4 × 1–2 mm;

anthers ovate, 0.3–0.4 mm.

Fruiting pedicels

horizontal to divaricate-ascending, straight, 3–14(–19) mm (subequaling or shorter than fruit), usually glabrous, rarely pubescent, trichomes 2–4-rayed.

divaricate-ascending (not decurrent basally), straight, 4–10 mm, glabrous.

Fruits

linear or, rarely, linear-elliptic, plane, flattened, (8–)10–17(–20) × 1.5–2 mm;

valves usually glabrous, rarely sparsely puberulent, trichomes simple;

ovules 24–36 per ovary;

style 0.01–0.15 mm.

ovate to oblong-elliptic, plane, flattened, 4–8 × 2–4 mm;

valves (obscurely veined), glabrous;

ovules 6–14 per ovary;

style 0.1–0.5 mm.

Seeds

ovoid, 0.9–1 × 0.5–0.6 mm.

ovoid, 1.2–1.5 × 0.8–1 mm.

2n

= 40.

Draba stenoloba

Draba daviesiae

Phenology Flowering Jun–Jul. Flowering Jul–Aug.
Habitat Grassy knolls, glacial moraines and creek banks, mesic meadows, alpine thickets Talus slopes, rock crevices and cracks, rocky ridges and slides, alpine meadows
Elevation 600-2300 m (2000-7500 ft) 2700-2900 m (8900-9500 ft)
Distribution
from FNA
AK; OR; WA; AB; BC; YT
[WildflowerSearch map]
[BONAP county map]
from FNA
MT
[BONAP county map]
Discussion

Draba stenoloba is occasionally confused with D. albertina, but is easily recognized by having exclusively 2–4-rayed (versus mostly simple) trichomes on stems proximally. It is rarely encountered and apparently confined to the Pacific Northwest. In contrast, D. albertina is common and widespread in the mountains of western North America.

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

Although originally described as a variety of Draba apiculata (= D. globosa), D. daviesiae is distinct morphologically. It is easily distinguished from the former by its densely pulvinate habit, obtuse leaf blades, and obscurely veined fruit valves. By contrast, D. globosa exhibits a cespitose but non-pulvinate habit, acute leaf blades, and prominently veined fruit valves. Draba daviesiae is known from the Bitterroot Mountains in Ravalli County.

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

Source FNA vol. 7, p. 340. FNA vol. 7, p. 305.
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. 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. 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. 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. acinacis, D. hirta var. siliquosa, D. macouniana, D. nemorosa var. stenoloba, D. nitida var. praelonga, D. oligantha, D. stenoloba var. oligantha D. apiculata var. daviesiae, D. densifolia var. daviesiae
Name authority Ledebour: Fl. Ross. 1: 154. (1841) (C. L. Hitchcock) Rollins: Contr. Gray Herb. 214: 5. (1984)
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