Draba norvegica |
Draba mulliganii |
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Norwegian Draba |
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Habit | Perennials; (cespitose); caudex branched (sometimes with persistent leaf remains); often scapose. | Perennials; (cespitose); caudex branched (with persistent leaves); often scapose. |
Stems | branched or unbranched, (0.2–)0.4–1.4(–2) dm, pubescent throughout, trichomes simple and 2–4-rayed, 0.2–0.5 mm. |
unbranched, 0.3–1.2 dm, glabrous throughout or sparsely pubescent proximally, trichomes short-stalked, 4–10-rayed, (non-crisped). |
Basal leaves | rosulate; petiolate; petiole (0–0.5 cm), ciliate throughout; blade oblanceolate to narrowly obovate or narrowly lanceolate, 0.4–2.1 cm × 1.5–7 mm, margins with 1–3 teeth on each side, (ciliate, trichomes simple and 2-rayed, 0.2–0.8 mm), surfaces pubescent abaxially with stalked, (2–)4(–6)-rayed trichomes, 0.1–0.4 mm, adaxially glabrous or pubescent, with simple and stalked, 2-rayed trichomes, 0.1–0.5 mm. |
rosulate; subsessile or shortly petiolate (petiolar base and proximal margin ciliate with stiff, subsetiform, simple trichomes, 0.3–0.6 mm); blade oblanceolate or lanceolate, 5–9 × 1–2 mm, margins entire, surfaces usually pubescent, abaxially with short-stalked, 8–12-rayed, stellate, (non-crisped) trichomes, 0.1–0.3 mm (often without spurred rays), rarely glabrescent, trichomes confined to margin, (midvein and petiole not thickened), adaxially with similar stellate and some simple trichomes. |
Cauline leaves | 0–3(–5); sessile; blade ovate to oblong, margins often dentate, (ciliate). |
0. |
Racemes | 5–23-flowered, ebracteate or proximalmost 1(–3) flowers bracteate, considerably elongated in fruit; rachis slightly or not flexuous, pubescent as stem. |
3–11-flowered, ebracteate, elongated in fruit; rachis not flexuous, glabrous. |
Flowers | sepals ovate, 1.7–2.5 mm, pubescent, (trichomes simple and short-stalked, 2–4-rayed); petals white, spatulate, 2.5–4 × 1.7–2.5 mm; anthers ovate, 0.3–0.4 mm. |
sepals (caducous), ovate, 1.7–2.2 mm, pubescent subapically, (trichomes simple and 2-rayed); petals white, broadly obovate, 3.2–4 × 2–3 mm, (apex obtuse); anthers ovate, 0.4 mm. |
Fruiting pedicels | suberect to ascending (often appressed to rachis), straight, (1.5–)2.5–5(–9) mm, pubescent, trichomes simple and 2–4-rayed. |
divaricate to ascending (not appressed to rachis), straight, (4–)5–9 mm, glabrous. |
Fruits | (sometimes subappressed to rachis), oblong to lanceolate-elliptic, plane, flattened, 4–8 × 2–3 mm; valves glabrous or pubescent, trichomes simple and short-stalked, 2-rayed, 0.05–0.25 mm; ovules 18–26 per ovary; style (0.01–)0.1–0.4(–0.5) mm, (glabrous, stigma about as wide as style). |
ovate-lanceolate to oblong, not twisted, flattened, 5–8 × 2–2.5 mm; valves glabrous; ovules 12–16 per ovary; style 0.4 1 mm. |
Seeds | oblong, 0.9–1.2 × 0.5–0.7 mm. |
ovoid, 0.7–1.1 × 0.5–0.6 mm. |
2n | = 48. |
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Draba norvegica |
Draba mulliganii |
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Phenology | Flowering Jun–Aug. | Flowering Jun–Jul. |
Habitat | Rock outcrops and sea cliffs, talus, gravelly and sandy terraces, moist bluffs, turfy limestone shores | Limestone gravel around outcrops, limestone crevices, dry serpentine knolls in heath vegetation with patches of exposed slide rock, shale rubble slopes |
Elevation | 0-500 m (0-1600 ft) | 300-1600 m (1000-5200 ft) |
Distribution |
NL; NS; NT; QC; Greenland; Europe (Finland, Norway, n Russia, Scotland, Sweden); Atlantic Islands (Iceland) |
AK |
Discussion | Draba norvegica is a highly variable hexaploid taxon and, as delimited herein, it probably represents two taxa with the same distribution and same chromosome number. It is related to hexaploid D. arctogena, from which it is distinguished by characteristics listed under 8. D. arctogena. Draba norvegica was divided by O. E. Schulz (1927) into eight varieties, whereas R. C. Rollins (1993) recognized just two. In the latter treatment, var. clivicola is distinguished by having predominantly branched, appressed trichomes on stems proximally, lanceolate, glabrous fruits, and slender, erect-appressed pedicels. By contrast, var. norvegica is said to have predominantly simple, spreading trichomes on stems proximally, narrowly ovate to elliptical, glabrous or pubescent fruits, and stout, divaricately ascending pedicels. These differences are extremes of a continuum, and we agree with G. A. Mulligan (1970) in reducing D. clivicola to synonymy of D. norvegica. Rollins indicated that D. norvegica grows in Minnesota, but we have not seen any material from that state. Draba norvegica is found in Europe in arctic and subarctic areas. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Source | FNA vol. 7, p. 322. | FNA vol. 7, p. 321. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | D. clivicola, D. hirta var. norvegica, D. norvegica var. clivicola, D. norvegica var. hebecarpa, D. rupestris, D. scandinavica var. hebecarpa, D. trichella | |
Name authority | Gunnerus: Fl. Norveg. 2: 106. (1772) | Al-Shehbaz: Harvard Pap. Bot. 14: 85. (2009) |
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