Salix reticulata L.
Net-vein willow.
Sp. pl. 2: 1018. 1753.
Salix orbicularis Anderss.
Salix reticulata subsp. orbicularis (Anderss.) Flod.
Salix reticulata var. gigantifolia Ball
Salix reticulata var. glabra Trautv.
Salix reticulata var. orbicularis (Anderss.) Komarov
Salix reticulata var. semicalva Fern.
Plants dwarf shrubs; less than 15 cm high; 3–15 cm high; forming colonies by layering. Stems. Aerial stems prostrate. Branches yellow-brown, or red-brown; not glaucous, or thinly glaucous (sometimes); glabrous; epidermis not flaky. Branchlets yellow-brown, or red-brown; not glaucous, or thinly glaucous (sometimes); glabrous. Bud scale inner membrane fused to outer layer. Stipules. Stipules present; scale-like. Petioles. Petioles (3–)10–25(–46) mm long; glandular dots at the base of the leaf present, or glandular dots at the base of the leaf absent; deeply concave in cross-section, but margins not covering the groove, or deeply concave in cross-section, margins covering groove; glabrous. Leaves. Juvenile leaves yellowish green; glabrous. Blades 1.2–6.6 cm long; 8–50 mm wide; length-width ratio 1–1.5; herbaceous, or leathery; oblong (to broadly oblong), or elliptic (broadly elliptic to subcircular), or circular; revolute; secondary veins impressed into adaxial surface, protruding on abaxial surface; secondary veins mostly arising at or close to a single point at base and running in recurved arches toward leaf apex; stomata on both adaxial and abaxial surfaces, or stomata on adaxial surface only present along veins or at apex. Blades adaxial surface shiny, or highly glossy; glabrous (rarely sparsely villous). Blades abaxial surface glabrous, or hairy, or glabrescent; glaucous; hairs long-silky; hairs sparse; hairs white, or translucent; hairs appressed; hairs straight. Leaf bases obtuse, or attenuate, or cordate. Leaf margins entire and glandular-dotted, or crenate (crenulate); with teeth all around leaf, or toward base only; with teeth per cm 2–9 (6); with submarginal glands. Leaf margins with glandular hairs all around leaf, or toward base only. Leaf apices rounded, or retuse (rarely retuse).
Plants dioecious. Catkins. Catkins flowering with the opening of leaf buds; catkins terminal on previous year’s shoot. Male catkins. Male catkins moderately densely flowered (more than 12 flowers per ament); 6–52 mm long; 4–7 mm wide; stout, or subglobose, or slender; peduncles 4–26 mm long; borne on a flowering branchlet; flowering branchlets 2–32 mm long. Female catkins. Female catkins densely flowered (more than 6 flowers per ament); 6–60 mm long; 3–8 mm wide; slender, or stout; peduncles 5–31 mm long; borne on a flowering branchlet; flowering branchlets 2–45 mm long. Floral bracts. Floral bracts tawny; widest at middle, or widest toward tip; 0.8–1.8 mm long; glabrous (rarely hairy at prox end); entire. Stamens 2; filaments hairy all over, or hairy on lower half. Anthers purple becoming yellow; ellipsoid, or subglobose; axis straight; 0.3–0.4 mm long. Male flowers. Male flowers abaxial nectaries one; adaxial nectaries two, or several; adaxial nectaries ovate, or broad-rod, or half-cup-shaped; adaxial nectaries 0.5–0.8 mm long; adaxial nectaries partially connected at base, or cup-shaped. Female flowers. Female flowers adaxial nectaries absent, or one, or two; two or more lobes; slender-rod; 0.5–0.8 mm long; equal to stipes, or longer than stipes; nectaries separate, or partially connected. Stipes 0–0.8 mm long. Ovaries inverse club-shaped, or pear-shaped; ovary slightly bulged at the base of the style, or abruptly tapering to style; hairy; ovary hairs short-silky. Ovary hair moderately dense, or dense; white, or translucent, or mixture of white, or translucent, and rust-coloured; appressed, or spreading; straight, or wavy; flattened. Styles 0.2–0.3 mm long. Stigmas broad-cylindrical; lobes 0.2–0.26–0.32 mm long. Ovules 8–18. Fruit. Fruit 4.5–5 mm long; glabrescent (sparsely).
Chromosome inforamtion. 2n = 38. Löve 1954; Hedberg 1967; Suda & Argus 1969; Packer & McPherson 1974; Löve & Löve 1982. Russia, Zhukova 1967, 1980; Zhukova et al. 1977; Zhukova & Petrovsky 1976, 1977; Petrovsky & Zhukova 1983b. Ploidy levels recorded 2x.
Distribution. Northern hemisphere: Greenland, Canada, United States, Eurasia (circumpolar). Canada: Alta., B.C., Lab., Man., Nfld., Ont., Que., Sask., Yukon, N.W.T., Nunavut. USA: Alaska, Colo., N.Mex., Oreg., Utah, Wyo.
Ecology and habitat. A dwarf shrub forming mats in moist tundra on gravel and sand beaches, stream banks, colluvial slopes, edges of frost polygons, and snowbeds. Usually in places well protected by winter snow cover. Often but not exclusively on calcareous substrates.
Notes. Salix reticulata is a dwarf species with stems that trail on the surface or in moss; leaves that are usually broad to circular-elliptic, with an adaxial surface that is prominently reticulate with impressed venation; its catkins are borne on flowering branchlets that are indistinguishable from normal vegetative branchlets, some plants have almost all branchlets ending in a catkin.
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Illustrations. • Habit. Salix reticulata subsp. reticulata: a female plant forming a prostrate mat. The leaf surface is prominently impressed-reticulate above. Almost all vegetative shoots end in a catkin. Photo taken at Victoria Island, Cambridge Bay, Nunavut, by Lynn Gillespie, July 1997. Voucher specimen: Laurie Consaul and Lynn Gillespie 1106, CAN. • Habit. Salix reticulata subsp. reticulata: habit, scale bar in cm. Photo taken at Iqaluit, Baffin Island, Nunavut, Aug. 1997. Voucher specimen: Susan Aiken and Cheryl McJannet 97015, CAN. • Male plant. Salix reticulata subsp. reticulata: male plant forming a mat. The leaves are prominently reticulate above. Photo taken by Donald Gunn; slide number: S84–5380, Photo Library, Canadian Museum of Nature. • Habitat. Salix reticulata subsp. reticulata: plants forming mats on stone stripes in alpine area. Photograph taken at Robb Lake, British Columbia, 1 Aug. 1977. • Habitat. Salix reticulata subsp. reticulata: habitat. Photo taken at Cambridge Bay, Victoria Island, Nunavut, by Lynn Gillespie, July 1997. Voucher specimen: Laurie Consaul and Lynn Gillespie 1106, CAN. • Habitat. Salix reticulata: Photo taken at Nunavut, Baffin Island, Iqaluit, Susan Aiken 97–015. • Leaf close-up. Salix reticulata subsp. reticulata: Leaf close-up. Photo taken at Cambridge Bay, Victoria Island, Nunavut, by Lynn Gillespie, July 1997. Voucher specimen: Laurie Consaul and Lynn Gillespie 1106, CAN. • Line drawing. Salix reticulata subsp. reticulata: A. Male catkins are borne on leafy, flowering branchlets. B. Male flowers have 2 stamens, hairy filaments, a glabrous floral bract and two floral nectaries (adaxial and abaxial) which form a cup at the base of the stamens. C. Female catkins are borne on leafy flowering branchlets. They have a long peduncle. D. Female flowers have a short, silky ovary, a short style, and a cup-like nectary surrounding the base of the ovary. • Arctic Island Distribution.
Cite this publication as: G.W. Argus, C.L. McJannet and M.J. Dallwitz (1999 onwards). ‘Salicaceae of the Canadian Arctic Archipelago: Descriptions, Illustrations, Identification, and Information Retrieval.’ Version: 2nd November 2000. http://http://www.mun.ca/biology/delta/arcticf/. Dallwitz (1980) and Dallwitz, Paine and Zurcher (1993, 1995, 2000) should also be cited (see References).
