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

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

weber's Draba

Habit Perennials; (cespitose, forming tufts); caudex branched (with persistent leaf bases, branches some terminating in sterile rosettes); scapose. Perennials; (cespitose); caudex branched (covered with persistent, somewhat thickened, petioles); not 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.

unbranched, 0.2–0.6(–1) dm, glabrous or sparsely pubescent throughout, trichomes simple, sessile or subsessile, 2- or 3-rayed, 0.2–0.6 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).

rosulate; petiolate;

petiole margin ciliate, (trichomes simple, 0.2–0.6 mm);

blade linear-oblanceolate, 0.4–1.5 cm × 0.8–1.7 mm, margins entire, (pubescent as petiole), surfaces pubescent abaxially with (appressed), simple, subsessile or sessile, 2–4-rayed trichomes, 0.1–0.4 mm, glabrous or subapically sparsely pubescent adaxially with simple trichomes.

Cauline leaves

0.

1–3;

sessile;

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

Racemes

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

rachis not flexuous, pubescent as stem or glabrous.

5–15-flowered, ebracteate, elongated in fruit;

rachis not flexuous, glabrous or pubescent as stem.

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.

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

petals yellow, spatulate, 3–4 × 1.2–1.8 mm, (flared, clawed);

anthers ovate, 0.3–0.4 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.

divaricate-ascending, straight, 2–6 mm, glabrous or sparsely pubescent as stem.

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.

ovate, plane, flattened, 4–8 × 2–3 mm;

valves glabrous;

ovules 16–18 per ovary;

style 0.2–0.3 mm.

Seeds

oblong, 1.5–2 × 1–1.3 mm.

ovoid, 1–1.2 × 0.6–0.7 mm.

2n

= 72.

Draba ruaxes

Draba weberi

Phenology Flowering Jun–Jul. Flowering Jun–Jul.
Habitat Rock outcrops, talus slopes, ridges, alpine summits Rock crevices along streamlets near timberline
Elevation 500-2400 m (1600-7900 ft) ca. 3500 m (ca. 11500 ft)
Distribution
from FNA
AK; WA; AB; BC; YT
[WildflowerSearch map]
[BONAP county map]
from FNA
CO
[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.)

Of conservation concern.

Draba weberi is an apomictic species allied to D. exunguiculata, D. grayana, and D. streptobrachia. From those, it is distinguished by having ovate fruits, clawed petals, and sessile, 2–4-rayed trichomes with untwisted rays often appressed to leaf and stem surfaces. Draba weberi is known from near North Star Peak in central Colorado (Summit County).

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

Source FNA vol. 7, p. 334. FNA vol. 7, p. 346.
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. 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. subalpina, D. subcapitata, D. subumbellata, D. trichocarpa, D. ventosa, D. verna, D. viridis, D. yukonensis, D. zionensis
Synonyms D. ventosa var. ruaxes
Name authority Payson & H. St. John: Proc. Biol. Soc. Wash. 43: 117. (1930) R. A. Price & Rollins: Harvard Pap. Bot. 1(3): 75, fig. 3. (1991)
Web links