Salix reticulata
Salix silicicola
net-leaf willow, net-vein willow, netted willow
blanket-leaf willow
trailing;
branches and branchlets yellow-brown or red-brown, glabrous.
branches yellow-brown, gray-brown, or red-brown, not glaucous, villous in patches to glabrescent;
branchlets gray-brown or red-brown, very densely villous.
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 foliaceous, apex acute to acuminate;
petiole convex to flat adaxially, 5–12 mm, villous or tomentose adaxially, (strongly ventricose around floral buds);
largest medial blade (apparently hypostomatous but surfaces obscured by hairs), narrowly oblong, narrowly elliptic, elliptic, or obovate, 36–84 × 19–40 mm, 1.8–3.6 times as long as wide, base convex or cuneate, margins slightly revolute, entire, apex convex or acuminate, abaxial surface very densely woolly-tomentose, hairs wavy, adaxial dull, moderately to very densely, villous-tomentose;
proximal blade margins entire;
juvenile blade color obscured by hairs, very densely tomentose-woolly abaxially, hairs white.
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.
adaxial nectary oblong to narrowly oblong, 0.6–1.5 mm;
filaments distinct;
anthers yellow, ellipsoid, 0.6–0.7 mm.
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.
adaxial nectary oblong or obtriangular, 0.5–1.1 mm;
stipe 0–0.3 mm;
ovary pyriform, beak gradually tapering to styles;
ovules 12–14 per ovary;
styles 1.2–2.2 mm;
stigmas 0.52–0.75–1 mm.
4.5–5 mm.
4–7 mm.
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.
flowering before leaves emerge; staminate stout, 40–56 × 14–15 mm, flowering branchlet 0 mm; pistillate densely flowered, slender, 35–125(–130 in fruit) mm, flowering branchlet 0 mm;
floral bract brown or black, 2–3 mm, apex convex to rounded, abaxially hairy, hairs straight.
= 38.
= 38.
Salix reticulata
Salix silicicola
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.)
Comparisons of genetic variation in Salix alaxensis var. alaxensis from British Columbia and S. silicicola from Lake Athabasca sand dunes, Saskatchewan, based on isozyme loci, fit predicted relationships between progenitor and derived taxon (B. G. Purdy and R. J. Bayer 1995). Allelic diversity of S. silicicola was a subset of that of S. alaxensis, there was less genetic variation in S. silicicola than in S. alaxensis, and interspecific genetic variation within the two species was similar and relatively very high. This suggested a recent origin for the derived S. silicicola.
Salix silicicola is a uniform population that differs from S. alaxensis in its very densely villous or tomentose leaves and branchlets. These characters seem to be an adaptation to reduce sand abrasion and water loss in a sand dune environment. It is unlikely that it would have evolved in situ but probably derived from a pre-adapted source such as the one represented by specimens of putative S. silicicola from Pelly Lake, Nunavut. The isozyme study did not include specimens from that population or of S. alaxensis from Northwest Territories from which S. silicicola is likely to have been derived. Occurrence of S. silicicola-like plants in northern continental Nunavut suggests that during the late Pleistocene, it had a wider range, which now is represented by two disjunct populations. The question of appropriate taxonomic rank for the derived taxon is still unresolved. Although S. silicicola is different from S. alaxensis in its general appearance, they are very similar genetically, and argument could be made for treating them as varieties (B. Boivin 1966b).
Hybrids:
Salix silicicola forms natural hybrids with S. brachycarpa var. psammophila.
of conservation concern
(Discussion copyrighted by Flora of North America; reprinted with permission.)
BC
OR
Flora NW
PNW Herbaria
WildflowerSearch
iNaturalist
USDA Plants Database
