Salix reticulata
Salix arizonica
net-leaf willow, net-vein willow, netted willow
Arizona willow
trailing;
branches and branchlets yellow-brown or red-brown, glabrous.
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 convex or rounded;
petiole convex to flat, or shallowly grooved adaxially, 2–7.5 mm, villous or pubescent to glabrescent adaxially;
largest medial blade (sometimes amphistomatous), elliptic or broadly elliptic, 20–50 × 10–31 mm, 1.6–2–2.8(–3.6) times as long as wide, base convex, rounded, or cordate, margins flat, serrulate or entire, apex acute, convex, or acuminate, abaxial surface not glaucous, pilose or glabrous, hairs wavy, adaxial slightly glossy, pilose or glabrous;
proximal blade margins entire, serrulate, or crenulate;
juvenile blade green, glabrous or pilose 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 narrowly oblong to oblong, 0.4–0.8 mm;
filaments distinct, glabrous;
anthers purple turning yellow, 0.4–0.6 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 narrowly oblong to oblong, 0.4–1 mm, shorter to longer than stipe;
stipe 0.2–1 mm;
ovary pyriform, glabrous, beak gradually tapering to or slightly bulged below styles;
ovules 8–12 per ovary;
styles 0.5–1.2 mm;
stigmas broadly cylindrical, 0.14–0.21–0.36 mm.
4.5–5 mm.
3.2–4.5 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 as leaves emerge; staminate stout, subglobose, or globose, 7–17 × 6–10 mm, flowering branchlet 1–3 mm; pistillate densely or moderately densely flowered, stout or subglobose, 12–38 × 6–12 mm, flowering branchlet 1.5–10 mm;
floral bract brown, black, or bicolor, 1–2 mm, apex acute or convex, abaxially hairy, hairs wavy.
= 38.
= 38.
Salix reticulata
Salix arizonica
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.)
Of conservation concern.
Salix arizonica is very similar to S. boothii. They were separated by Dorn on the presence of five flavonoid compounds identified in S. boothii not found in S. arizonica. Some morphological differences were noted but the characters used to separate them are quite variable. The most important feature seems to be the usually broader leaves of S. arizonica. In addition, the diploid chromosome number for S. arizonica separates it from the tetraploid S. boothii. Although the two are distinct species, the overlap in their morphological characters suggests that positive identification needs to be based on chromosome number or chromatographic analysis.
Salix arizonica is distinguished from S. boothii by having stipule apices convex to rounded, petioles 3–7.5 mm, juvenile blades glabrous or hairy, hairs white, largest medial blades elliptic or broadly elliptic, 20–50 mm, 1.6–3.6 times as long as wide, abaxial surfaces with white hairs, staminate catkins 1–1.7 times as long as broad, pistillate catkins 1.2–2.8 times as long broad, floral bract apices acute to convex, nectaries narrowly oblong to oblong, staminate nectaries 0.4–0.8 mm, anthers 0.4–0.6 mm, filaments distinct, glabrous, pistillate nectaries shorter to longer than stipes, stipes 0.2–1 mm, stigmas broadly cylindrical, and capsules 3.2–4.5 mm; S. boothii has stipule apices acuminate or acute to rounded, petioles 3–17 mm, juvenile blades hairy, hairs white, sometimes also ferruginous, largest medial blades lorate to narrowly or broadly elliptic, 26–102 mm, 2–5.2 times as long as wide, abaxial surfaces with white, sometimes also ferruginous, hairs, staminate catkins 1.2–3.1 times as long as broad, pistillate catkins 1.4–4.1 times as long as broad, floral bract apices rounded or retuse, nectaries narrowly oblong to ovate or flask-shaped, staminate nectaries 0.6–1.5 mm, anthers 0.48–0.8 mm, filaments distinct to connate about half their lengths, glabrous or hairy, pistillate nectaries shorter than stipes, stipes 0.5–2.5 mm, stigmas flat, abaxially non-papillate with rounded tip, slenderly cylindrical or plump, and capsules 2.5–6 mm.
Salix arizonica, originally known from Mt. Baldy in east-central Arizona, was proposed for listing under the United States Endangered and Threatened Wildlife and Plants Act, but the proposal was withdrawn when additional populations were discovered in southern Utah and in New Mexico; it is now listed as a “sensitive species” (K. Decker, www.fs.us/r2/projects/scp/assessments/salixarizonica.pdf). Major conservation concerns are from browsing by cattle and elk (J. Maschinski 2001) and Melampsora infection (M. L. Fairweather 1993; R. A. Obedzinski et al. 2001). The Arizona populations receive minimal protection from cattle and wildlife browsing by exclosures and by introduction into new localities. The Arizona and Utah populations have a genetic similarity of ca. 37%, which has been attributed to a period of panmixis followed by a long period of isolation in regions with different environments (J. T. Thompson et al. 2003).
Salix arizonica is in the Center for Plant Conservation’s National Collection of Endangered Plants.
Hybrids:
Salix arizonica forms natural hybrids with S. brachycarpa, S. eastwoodiae, and S. lutea.
Salix arizonica × S. brachycarpa var. brachycarpa occurs in southern Utah. Its parentage is supported by chromatographic data (E. D. McArthur, pers. comm.).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
BC
OR
Flora NW
PNW Herbaria
WildflowerSearch
iNaturalist
USDA Plants Database
