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coast mountain Draba, coast mountain whitlow-grass, coast mountain whitlow-grass Draba, Rainier Draba

Habit Perennials; (cespitose, forming tufts); caudex branched (with persistent leaf bases, branches some terminating in sterile rosettes); scapose.
Stems

unbranched, 0.2–0.6(–0.8) dm, often pubescent throughout, sometimes glabrate distally, trichomes simple, 0.4–1 mm, and 2–4-rayed, 0.1–0.4 mm.

Basal leaves

rosulate;

subsessile;

petiole base and margin ciliate, (trichomes simple, 0.4–1.4 mm);

blade oblanceolate to obovate or suborbicular, 0.3–1 cm × 2–4.5 mm, margins entire, surfaces pubescent, abaxially with stalked, 2–10-rayed, stellate trichomes, 0.2–0.8 mm, adaxially with simple trichomes, 0.4–1 mm, sometimes with smaller, 2–4-rayed ones, (midvein obscure).

Cauline leaves

0.

Racemes

(2–)4–10(–14)-flowered, ebracteate, elongated in fruit;

rachis not flexuous, pubescent as stem or glabrous.

Flowers

sepals ovate, 2–3 mm, pubescent, (trichomes simple with fewer, 2-rayed ones);

petals bright yellow, obovate, 4–6 × 2–3.5 mm;

anthers oblong, 0.4–0.5 mm.

Fruiting pedicels

ascending to divaricate-ascending, straight or slightly curved upward, 3–7(–9) mm, pubescent or glabrous, trichomes simple and 2–4-rayed.

Fruits

elliptic to lanceolate or ovate to suborbicular, plane, flattened, 4–8(–10) × 3–4.5 mm;

valves puberulent, trichomes simple with fewer 2-rayed ones, 0.1–0.35 mm;

ovules 12–16 per ovary;

style 0.5–0.9(–1.1) mm.

Seeds

oblong, 1.5–2 × 1–1.3 mm.

2n

= 72.

Draba ruaxes

Phenology Flowering Jun–Jul.
Habitat Rock outcrops, talus slopes, ridges, alpine summits
Elevation 500-2400 m (1600-7900 ft)
Distribution
from FNA
AK; WA; AB; BC; YT
[WildflowerSearch map]
[BONAP county map]
Discussion

C. L. Hitchcock (1941) treated Draba ruaxes as a variety of D. ventosa; as demonstrated by G. A. Mulligan (1971b), the two are quite distinct. Draba ruaxes is an outcrossing hexaploid with well-formed anthers and pollen, and abundant, simple trichomes on leaves, stems, sepals, and fruits. By contrast, D. ventosa is an apomictic triploid with abortive anthers and/or pollen, and no simple trichomes anywhere on the plant.

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

Source FNA vol. 7, p. 334.
Parent taxa 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. 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. ventosa var. ruaxes
Name authority Payson & H. St. John: Proc. Biol. Soc. Wash. 43: 117. (1930)
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