Flora of North America species comparison

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Draba albertina

Draba pectinipila

Alaska Draba, Alaska whitlow-grass, Alberta whitlow grass, slender Draba, slender whitlow-grass
Habit Annuals, biennials, or perennials; caudex (or base) simple or branched (poorly developed); rarely scapose. Perennials; (cespitose, sometimes forming mats); caudex branched (with persistent leaf bases, branches creeping, terminating in scapes or sterile rosettes); scapose.
Stems

branched distally, (0.3–)0.5–3(–4.2) dm, pubescent proximally, often glabrous distally, trichomes simple, 0.1–1 mm, sometimes with fewer, stalked, 2-rayed ones.

unbranched, (0.3–)0.4–1.6(–1.9) dm, pubescent, trichomes sessile, pectinate, 0.1–0.4 mm, (parallel to long axis of stem, sometimes with irregularly 2–4-rayed ones, 0.2–0.6 mm).
Basal leaves

rosulate; shortly petiolate;

petiole (0–0.5 cm), ciliate throughout;

blade obovate to oblanceolate or linear-lanceolate, (0.3–)1–2.8(–3.5) cm × (1–)2–6(–9) mm, margins entire or denticulate, (ciliate, trichomes simple, 0.4–1 mm), surfaces usually pubescent, abaxially with stalked, 2–4-rayed trichomes, 0.05–0.4(–0.5) mm, (rarely with simple trichomes along midvein), adaxially with simple trichomes sometimes also with 2-rayed ones, 0.07–0.4 mm, rarely glabrous.

rosulate;

subsessile;

blade narrowly oblanceolate to linear, (0.4–)0.6–1.3(–2) cm × 0.9–2.2 mm, margins entire (not ciliate), surfaces pubescent with subsessile or sessile, pectinate trichomes, 0.2–0.5 mm.
Cauline leaves

(0 or) 1–3(–5);

sessile;

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

0.
Racemes

(2–)6–30(–50)-flowered, ebracteate, elongated in fruit;

rachis straight or, rarely, flexuous, glabrous.

5–22-flowered, ebracteate, considerably elongated in fruit;

rachis not flexuous, pubescent as stem.
Flowers

(chasmogamous, petaliferous);

sepals ovate, 1.4–2.1 mm, glabrous or sparsely pubescent, (trichomes simple);

petals yellow, spatulate to oblanceolate, 2–3.2 × 0.7–1.2 mm;

anthers ovate, 0.15–0.25 mm.

sepals broadly ovate, 2–3.2 mm, pubescent, (trichomes pectinate);

petals yellow, obovate to spatulate, 4–6.5 × 1.5–2.5 mm;

anthers ovate 0.4–0.5 mm.
Fruiting pedicels

divaricate-ascending or horizontal, (not appressed to rachis), usually straight, rarely curved upward, (3–)5–14(–16) mm (subequaling or shorter than fruit), usually glabrous, rarely sparsely puberulent.

divaricate-ascending, straight, (5–)7–14 mm, sparsely pubescent, trichomes pectinate.
Fruits

lanceolate to narrowly elliptic or linear, plane, flattened, (4–)6–12(–15) × (1–)1.4–2.1 mm;

valves glabrous;

ovules (20–)24–38(–44) per ovary;

style 0.01–0.12 mm.

ovoid, plane, slightly inflated basally, 4–6(–7) × 2–3 mm;

valves pubescent, trichomes usually sessile, pectinate, 0.2–0.5 mm, rarely with simple ones;

ovules 4–8 per ovary;

style 0.5–1.5 mm.
Seeds

oblong, 0.7–1 × 0.4–0.5 mm.

oblong, 1.1–1.5 × 0.6–0.8 mm.
2n

= 24.

= 22.

Draba albertina

Draba pectinipila
Phenology Flowering Jun–Aug. Flowering Apr–Jun.
Habitat Open woodlands, pine forests, meadows, rocky knolls, alpine slopes, stream banks, disturbed areas Rocky slopes in sagebrush scrub and pinyon-juniper woodlands
Elevation 900-3700 m (3000-12100 ft) 1700-2400 m (5600-7900 ft)
Distribution
from FNA
AK; AZ; CA; CO; ID; MT; NM; NV; OR; UT; WA; WY; AB; BC; NT; YT
[WildflowerSearch map]
[BONAP county map]
from FNA
CO; MT; UT; WY
[BONAP county map]
Discussion

O. E. Schulz (1927) and C. L. Hitchcock (1941) confused the limits of Draba albertina, D. crassifolia, and D. stenoloba; the latter author treated the first two species as conspecific. G. A. Mulligan (1975) demonstrated that the three taxa are chromosomally and morphologically distinct (see D. crassifolia and D. stenoloba for differences from D. albertina). The ranges of D. albertina and D. crassifolia overlap extensively, and occasional sterile hybrids are encountered.

The Alaskan record of Draba albertina is based on Minard 4 (ALA), collected on the northern coast of Afognak Island (58°22’N, 152°28’W). The record from New Mexico is based on O’Kane & Hedin 3871 (ISTC, SJC), collected in Chuska Mountains (36°8’11”N, 108°54’19”W).

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

Draba pectinipila was treated as a synonym of D. oligosperma by G. A. Mulligan (1972), R. C. Rollins (1993), and N. H. Holmgren (2005b). The latter recognized D. juniperina as a distinct species but overlooked the fact that it is indistinguishable from the type collections of the earlier-published D. pectinipila. The species (including D. juniperina) differs significantly from D. oligosperma in both chromosome number and morphology. Draba pectinipila is easily distinguished by having fruit valves pubescent with pectinate trichomes, fruiting pedicels (5–)7–14 mm, petals 4–6.5 mm, ovules 4–8 per ovary, and styles 0.5–1.5 mm. By contrast, D. oligosperma has fruit valves glabrous or pubescent with simple or 2-rayed trichomes, fruiting pedicels (2–)3–10(–13) mm, petals 2.5–4 mm, ovules 6–12 per ovary, and styles 0.1–0.8(–1.1) mm. Draba pectinipila was previously known only from the type locality in northwestern Wyoming (Park County). Its range is now expanded to include that of D. juniperina in northwestern Colorado (Moffat County), northeastern Utah (Daggett and Uintah counties), and southwestern Wyoming (Sweetwater County). The record from Uintah County is based on Goodrich 22275 (NY).

(Discussion copyrighted by Flora of North America; reprinted with permission.)
Source FNA vol. 7, p. 288. FNA vol. 7, p. 328.
Parent taxa Brassicaceae > tribe Arabideae > Draba Brassicaceae > tribe Arabideae > Draba
Sibling taxa
D. abajoensis, 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. 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. 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. crassifolia var. albertina, D. crassifolia var. nevadensis, D. deflexa, D. nitida, D. nitida var. nana, D. stenoloba var. nana, D. stenoloba var. ramosa D. juniperina, D. oligosperma var. juniperina, D. oligosperma var. pectinipila
Name authority Greene: Pittonia 4: 312. (1901) Rollins: Rhodora 55: 231. (1953)
Web links 
Unless otherwise noted, all data comes from the online version of the Flora of North America, who have made most of their content available via a Creative Commons license (CC BY 4.0).



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