Salix reticulata |
Salix arctophila |
|
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net-leaf willow, net-vein willow, netted willow |
arctic willow, northern willow |
|
Habit | Plants 0.03–0.15 m, (dwarf, forming clones by layering). | Plants 0.03–0.15 m, (dwarf), forming clones by layering. |
Stems | trailing; branches and branchlets yellow-brown or red-brown, glabrous. |
prostrate, long-trailing; branches yellow-brown, red-brown, or green-brown, glabrous; branchlets yellow-green or yellow-brown to red-brown, (sometimes weakly glaucous), glabrous, (inner membranaceous bud-scale layer free, not separating from outer layer). |
Leaves | stipules absent or rudimentary; petiole 3–46 mm, (sometimes glandular distally); largest medial blade amphistomatous or hemiamphistomatous, (2 pairs of secondary veins arising at or close to base, arcing toward apex), oblong, broadly oblong, broadly elliptic, subcircular, or circular, (8–)12–66 × 8–50 mm, 1–1.5 times as long as wide, base convex, rounded, subcordate, or cordate, margins slightly revolute, entire or crenulate (glandular-dotted), apex rounded, convex, or retuse, abaxial surface sparsely long-silky to glabrescent, adaxial (venation deeply impressed), slightly or highly glossy, glabrous or pilose; proximal blade margins entire; juvenile blade glabrous. |
stipules rudimentary, absent, or foliaceous on early ones, foliaceous or rudimentary on late ones; petiole 3–7.8–15 mm; largest medial blade hypostomatous or hemiamphistomatous, elliptic, obovate, broadly elliptic, broadly obovate, subcircular, or oblanceolate, 15–31–60 × 6.5–16–35 mm, 1.2–3–4.3 times as long as wide, base cuneate, convex, or rounded, margins slightly revolute, inconspicuously crenulate or entire, apex usually acute or convex, sometimes rounded, abaxial surface glaucous, glabrous, adaxial slightly or highly glossy, glabrous; proximal blade margins entire or serrulate; juvenile blade glabrous. |
Staminate flowers | abaxial nectary 0.5–0.9 mm, adaxial nectary oblong or ovate, 0.5–1 mm, nectaries connate and cup-shaped; filaments distinct, hairy on proximal 1/2 or throughout; anthers ellipsoid or globose, 0.3–0.4 mm. |
abaxial nectary absent, adaxial nectary oblong, square, narrowly oblong, or ovate, 0.4–1 mm; filaments distinct or connate less than 1/2 their lengths, glabrous, or hairy on proximal 1/2; anthers ellipsoid or long-cylindrical, 0.5–0.7 mm. |
Pistillate flowers | abaxial nectary (0–)0.3–0.5 mm, adaxial nectary narrowly oblong, 0.5–1 mm, equal to or longer than stipe, nectaries distinct or connate and cup-shaped; stipe 0–0.8 mm; ovary pyriform or ovoid, short-silky, hairs flattened, beak abruptly tapering to styles; ovules 8–18 per ovary; styles connate to distinct 1/2 their lengths, 0.2–0.3 mm; stigmas flat, abaxially non-papillate with rounded tip, broadly cylindrical, or 2 plump lobes, 0.2–0.26–0.36 mm. |
abaxial nectary absent, adaxial nectary oblong or narrowly oblong, 0.5–0.9 mm, shorter than stipe; stipe 0.8–1.4 mm; ovary pyriform or obclavate, pubescent or short-silky, (refractive), hairs (white, grayish, or ferruginous), crinkled, often refractive, ribbonlike, beak gradually tapering to styles; ovules 8–16 per ovary; styles connate or distinct 1/2 their lengths, 0.6–1.4 mm; stigmas slenderly or broadly cylindrical, 0.24–0.47–0.72 mm. |
Capsules | 4.5–5 mm. |
5–9 mm. |
Catkins | staminate 11–54 × 4–9 mm, flowering branchlet 2–28 mm; pistillate densely flowered (more than 6 flowers), slender or stout, 11–79 × 3–8 mm, flowering branchlet 2–37 mm; floral bract tawny, 0.8–1.8 mm, apex rounded to retuse, entire, abaxially glabrous. |
staminate 19–54 × 7–16 mm, flowering branchlet 4–20 mm; pistillate densely to moderately densely flowered, slender to subglobose, 30–79(–130 in fruit) × 10–20 mm, flowering branchlet 8–57 mm; floral bract brown, black, or bicolor, 0.8–2.4 mm, apex rounded or acute, entire, abaxially densely hairy, hairs straight. |
2n | = 38. |
= 76. |
Salix reticulata |
Salix arctophila |
|
Phenology | Flowering early Jun-mid Aug. | Flowering late May-late Jul. |
Habitat | Arctic-alpine, polygonal tundra, dry tussock tundra, partially stabilized sand dunes, sedge meadows, Dryas tundra on alpine cliffs and ledges, snowbeds, stabilized talus slopes, white spruce woods, treed bogs | Arctic-alpine, subarctic, hummocks in wet, mossy, grass or sedge meadows, margins of streams or ponds, among granite boulders, on alluvial plains, sometimes in snowbeds |
Elevation | 0-3500 m (0-11500 ft) | 40-600 m (100-2000 ft) |
Distribution |
AK; CO; AB; BC; MB; NL; NT; NU; ON; QC; SK; YT; Europe; Asia (Chukotka, Russian Far East, arctic, e Siberia, Spitzbergen)
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AK; ME; MB; NL; NT; NU; ON; QC; SK; YT; Greenland
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Discussion | The reported occurrence of Salix reticulata in Colorado (R. D. Dorn 1997) needs further study. Salix reticulata occurs in Europe in northern Scotland, northern Scandinavia, the Alps and other European mountains, and arctic Eurasia. The species is circumpolar except for Greenland and Iceland. A population of Salix reticulata on the Queen Charlotte Islands, with consistently glabrous ovaries, was named subsp. glabellicarpa. Some southeastern Alaska populations have plants with glabrous, partially hairy, and completely short-silky ovaries growing together. The possibility that subsp. glabellicarpa may be a hybrid or a simple mutation needs study. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Salix arctophila occurs in western Greenland. Hybrids: Salix arctophila forms natural hybrids with S. arctica, S. glauca var. cordifolia, and S. uva-ursi. Salix arctophila × S. glauca var. cordifolia: Plants with villous leaves and moderately densely hairy branchlets and branches suggest this hybrid. Putative hybrids are rare but have been seen from Kuujjuaq and Ivujivik, Quebec (G. W. Argus, unpubl.), and are reported to be common in West Greenland (T. W. Böcher 1952). Salix arctophila × S. uva-ursi is a rare hybrid. The plants often have ovaries with patches of hairs, some of which are ribbonlike, as in S. arctophila, but their habit is compact, as in S. uva-ursi, rather than long-trailing as in S. arctophila. Some specimens are infertile and are evidently hybrids, but there is little to confirm S. uva-ursi as the second parent. N. Polunin (1940b) also expressed some uncertainty about plants intermediate between S. arctophila and S. uva-ursi, and A. K. Skvortsov (1971) discounted this hybrid but noted that there were a few somewhat doubtful specimens. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 7, p. 65. | FNA vol. 7, p. 73. |
Parent taxa | Salicaceae > Salix > subg. Chamaetia > sect. Chamaetia | Salicaceae > Salix > subg. Chamaetia > sect. Myrtosalix |
Sibling taxa | ||
Synonyms | S. reticulata var. gigantifolia, S. reticulata subsp. glabellicarpa, S. reticulata var. semicalva | S. arctophila var. lejocarpa, S. groenlandica var. lejocarpa |
Name authority | Linnaeus: Sp. Pl. 2: 1018. (1753) | Cockerell ex A. Heller: Cat. N. Amer. Pl. ed. 3, 89. (1910) |
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