Salix humboldtiana
Salix chlorolepis
Humboldt's willow
green-bract willow, greenscale willow
erect;
branches red-brown, (weakly glaucous), glabrous;
branchlets yellow-brown, glabrous.
stipules absent or rudimentary;
petiole (deeply to shallowly grooved adaxially), 1–3.5 mm;
largest medial blade elliptic, oblanceolate, or obovate, 14–33 × 7–12 mm, 1.9–3.4 times as long as wide, base cuneate or convex, margins flat or slightly revolute, entire, ciliate, apex acute, convex, or rounded, abaxial surface glabrous, adaxial slightly glossy, glabrous;
proximal blade margins entire;
juvenile blade (sometimes reddish), glabrous, ciliate.
abaxial nectary 0.3–0.4 mm, adaxial nectary oblong, 0.5–0.8 mm, nectaries distinct;
filaments distinct, glabrous;
anthers ellipsoid, 0.4–0.6 mm.
adaxial nectary narrowly oblong, 0.9–1.6 mm, longer than stipe, nectaries distinct or connate and shallowly cup-shaped;
stipe 0–0.4 mm;
ovary pyriform, glabrous, beak abruptly tapering to or slightly bulged below styles;
ovules 8–10 per ovary;
styles connate to distinct 1/2 their lengths, 0.5–1.3 mm;
stigmas flat, abaxially non-papillate with rounded tip, or slenderly cylindrical, 0.3–0.6 mm.
3.6–6 mm.
humboldtiana Willdenow: Humboldt willow is not known to occur in the flora area.
is characterized by: trees, 4–25 m;
branches highly brittle at base, bud-scale margins distinct and overlapping adaxially;
stipules on late leaves rudimentary or foliaceous;
largest medial leaf blade usually linear, abaxial surface not glaucous, adaxial dull;
pistillate bract deciduous after flowering;
stamens 3–7;
capsules with distinct, often raised, white veins.;
it occurs throughout much of Mexico to central Chile.
staminate 6.5 × 5–8 mm, flowering branchlet 1–3 mm;
pistillate densely flowered, stout or subglobose, 7–12 × 3–6 mm, flowering branchlet 1.8–12 mm;
floral bract tawny, brown, or greenish, 1–2.6 mm, apex broadly rounded to retuse, entire, abaxially glabrous.
= 38.
Salix humboldtiana
Salix chlorolepis
Salix humboldtiana is closely related to S. nigra in its generally narrow leaf blades, which are not glaucous abaxially. The two differ in the following characters: S. humboldtiana has leaf blades linear to sometimes narrowly oblong (10–28.6 times as long as wide), ovaries usually ovoid to ellipsoid, ovary walls often stomatiferous and with raised, white veins, and capsule valves relatively thick, slightly recurved. S. nigra has leaf blades usually narrowly lanceolate (6–13 times as long as wide), ovaries pyriform to obclavate, ovary walls neither stomatiferous nor notably veined, and capsule valves relatively thin and strongly recurved. Both species occur in Chihuahua, Mexico.
The report by R. I. Lonard et al. (1991) that specimens identified as Salix nigra from the lower Rio Grande, Texas, resemble S. humboldtiana in having strongly veined capsules suggests that S. humboldtiana, or intergrades with that species, may occur in Texas. Attempts to locate a voucher specimen were unsuccessful; because strongly veined capsules are diagnostic, further field study is indicated.
An earlier name, Salix chilensis Molina, has been applied to this species; it does not seem to pertain to this taxon (C. K. Schneider 1918).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Of conservation concern.
Salix chlorolepis, known from Mt. Albert, is characterized by its general glabrousness. It seems to have a relationship with S. brachycarpa similar to that of S. raupii to S. glauca. Both may have originated through mutation or hybridization.
Hybrids:
Salix chlorolepis forms natural hybrids with S. brachycarpa var. brachycarpa.
Salix chlorolepis × S. pedicellaris is a putative hybrid that has relatively small, glabrous leaves. Both parents occur together on Mt. Albert, Quebec.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
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