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whitlow-wort, Yellowstone Draba, Yellowstone Draba whitlow-wort, Yellowstone whitlow-grass, Yellowstone whitlow-wort

Santa Rita Mountain Draba, Santa Rita Mountain whitlowgrass, Santa Rita whitlow grass

Habit Perennials; (cespitose, often pulvinate); caudex branched (dense with persistent leaf remains, branches sometimes terminating in sterile rosettes); scapose. Perennials; (cespitose, long-lived); caudex simple or branched (covered with persistent petioles), not scapose.
Stems

unbranched, (0.2–)0.4–1.4(–2.1) dm, often pubescent throughout, sometimes glabrous distally, trichomes often simple and 2–5-rayed, 0.1–0.5 mm, (sometimes with mostly subpectinate ones).

usually unbranched, rarely branched, 0.3–1.9(–2.8) dm, moderately to densely hirsute throughout, trichomes simple, 0.2–1.3 mm, with short-stalked to subsessile, cruciform, 0.02–0.4 mm, and 2-rayed ones, 0.3–0.9 mm.

Basal leaves

rosulate; petiolate;

petiole (0–1 cm), ciliate throughout;

blade narrowly oblanceolate to linear, (0.4–)0.6–1.7(–2.5) cm × (1–)1.5–3.5(–5) mm, margins entire, (ciliate, trichomes usually simple, rarely 2-rayed, 0.2–1.1 mm), surfaces usually pubescent with short-stalked, pectinate trichomes, 0.15–0.5 mm, sometimes also with 4–6-rayed ones, (midvein usually obscure abaxially), sometimes glabrous adaxially.

rosulate; petiolate;

petiole ciliate, (trichomes simple, 0.4–1.5 mm);

blade oblanceolate, 1–5(–6) cm × 2–5(–10) mm, margins usually entire, rarely denticulate, surfaces pubescent, abaxially with stalked, cruciform trichomes, 0.07–0.5 mm, adaxially often similar, sometimes with fewer, simple and 2-rayed trichomes, 0.4–1.3 mm.

Cauline leaves

usually 0 (or 1, as a bract);

sessile;

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

3–10;

sessile;

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

Racemes

3–14(–30)-flowered, usually ebracteate, rarely proximalmost flowers bracteate, elongated in fruit;

rachis not flexuous, glabrous or pubescent as stem.

10–37(–58)-flowered, ebracteate, elongated in fruit;

rachis not flexuous, pubescent as stem.

Flowers

sepals broadly ovate, 2.5–3.5(–4) mm, pubescent, (trichomes simple and 2- or 3-rayed);

petals yellow (fading white), oblanceolate to obovate, 4–6 × 1.5–2.5 mm;

anthers ovate, 0.3–0.5 mm.

sepals oblong, 2–3.5 mm, pubescent, (trichomes simple and 2-rayed);

petals yellow, oblanceolate, 3.5–6 × 1.2–1.8 mm;

anthers oblong, 0.8–1 mm.

Fruiting pedicels

ascending, straight, (2.5–)4–11(–27) mm, glabrous or pubescent, trichomes 2–5-rayed or pectinate.

divaricate-ascending, straight, 4–10 mm, pubescent throughout, trichomes simple (0.1–0.5 mm) and subsessile, 2–4-rayed, (0.03–0.2 mm).

Fruits

broadly ovate to lanceolate, plane, flattened, 5–9(–11) × 2–4 mm;

valves glabrous or puberulent, trichomes simple and 2-rayed, 0.05–0.3 mm;

ovules 8–16(–20) per ovary;

style 0.2–0.9 mm.

lanceolate to elliptic, often strongly twisted, flattened, 5–11 × 2–3 mm;

valves puberulent at least along margin, trichomes simple, antrorse, 0.03–0.15 mm;

ovules 14–24 per ovary;

style 0.8–1.8(–2.5) mm.

Seeds

oblong, 1.1–1.5 × 0.7–1 mm.

ovoid, 1–1.4 × 0.6–0.9 mm.

2n

= 112.

Draba incerta

Draba petrophila

Phenology Flowering Jun–Aug. Flowering Jul–Sep.
Habitat Rock outcrops, talus, gravelly areas, tundra Crevices, ledges of cliffs
Elevation 0-3300 m (0-10800 ft) 1200-2800 m (3900-9200 ft)
Distribution
from FNA
AK; CO; ID; MT; NV; UT; WA; WY; AB; BC; QC; YT
[WildflowerSearch map]
[BONAP county map]
from FNA
AZ
[WildflowerSearch map]
[BONAP county map]
Discussion

Draba incerta was shown by G. A. Mulligan (1972) to be sexually reproducing and 14-ploid with x = 8. It is often confused with the apomict D. oligosperma (2n = 32, 64). Draba incerta is readily separated from D. oligosperma by having well-formed (versus abortive) anthers and pollen, stalked (versus sessile) leaf trichomes, and ciliate (versus non-ciliate) basal leaves with obscure (versus prominent) midveins. Although both species have leafless scapes, one often finds a bract adnate to, or subtending, the proximalmost pedicel in D. incerta.

Draba incerta is found near sea level in Alaska.

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

Draba petrophila is often broadly circumscribed to include the taxon herein called D. viridis. For a discussion of the differences between these species and the closely related D. helleriana, see I. A. Al-Shehbaz and M. D. Windham (2007). Draba petrophila, in the strict sense, is known only from Cochise, Pima, and Santa Cruz counties in southeastern Arizona.

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

Source FNA vol. 7, p. 313. FNA vol. 7, p. 329.
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. 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. 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. exalata, D. incerta var. laevicapsula, D. incerta var. peasei, D. laevicapsula, D. peasei D. helleriana var. blumeri, D. helleriana var. petrophila
Name authority Payson: Amer. J. Bot. 4: 261. (1917) Greene: Pittonia 4: 17. (1899)
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