Salix humboldtiana |
Salix sitchensis |
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Humboldt's willow |
Coulter willow, Sitka willow |
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Habit | Shrubs or trees, 1–8 m, (sometimes forming clones by stem fragmentation). | |
Stems | branches (sometimes highly brittle at base), yellow-brown or red-brown, not glaucous, glabrous or pilose; branchlets yellow-brown, gray-brown, or red-brown, densely short-silky, velvety, or villous, (buds caprea-type or intermediate). |
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Leaves | stipules absent or rudimentary on early ones, rudimentary or foliaceous on late ones, apex acute; petiole convex to flat, or shallowly grooved adaxially, 3–13(–16) mm, tomentose or velvety adaxially; largest medial blade elliptic, narrowly oblanceolate, oblanceolate, or obovate, 31–70–120 × 17–48 mm, 2.1–3.1–4 times as long as wide, base cuneate or convex, margins slightly revolute or flat, strongly revolute proximally, entire, irregularly serrate, or sinuate, (glands submarginal or epilaminal), apex acuminate or convex, abaxial surface not evidently glaucous, (obscured by hairs), densely short-silky, woolly, or silky-woolly, hairs straight, wavy, or curved, adaxial slightly glossy (sometimes dull and glaucous), pilose or moderately densely short-silky; proximal blade margins entire or shallowly serrulate; juvenile blade green, densely long-silky or woolly abaxially, (sparsely silky-tomentose adaxially), hairs white. |
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Staminate flowers | adaxial nectary narrowly oblong, oblong, ovate, or flask-shaped, 0.4–1.3 mm; stamens 1; filaments distinct, glabrous; anthers purple turning yellow, shortly cylindrical, 0.5–0.7 mm. |
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Pistillate flowers | adaxial nectary square, ovate, or flask-shaped, 0.5–0.9 mm, shorter to longer than stipe; stipe 0.4–1.4 mm; ovary ovoid to pyriform, long- or short-silky or villous, beak sometimes slightly bulged below styles; ovules 14–20 per ovary; styles 0.4–0.8 mm; stigmas flat, abaxially non-papillate with rounded tip, or broadly cylindrical, 0.16–0.28–0.4 mm. |
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Capsules | 3.5–5.6 mm. |
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Salix | humboldtiana Willdenow: Humboldt willow is not known to occur in the flora area. |
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It | 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. |
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Catkins | flowering just before or as leaves emerge; staminate slender or stout, (17–)22–54 × 8–15 mm, flowering branchlet 1–9 mm; pistillate moderately densely flowered, slender to stout, 25–73(–115 in fruit) × 5–15 mm, flowering branchlet 1–20 mm; floral bract tawny to dark brown, 1.4–2.4 mm, apex rounded or acute, abaxially hairy, hairs straight or wavy. |
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2n | = 38. |
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Salix humboldtiana |
Salix sitchensis |
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Phenology | Flowering early Apr-mid Jun (Mar in California). | |
Habitat | Tidal swamps and marshes, coastal fog belts and headlands, sand dunes, springs, gravelly streambeds and deltas, glacial moraines, avalanche tracks, dry canyons, clearings and edges of forests, shade tolerant | |
Elevation | 0-1800 m (0-5900 ft) | |
Distribution |
Mexico to central Chile |
AK; CA; ID; MT; OR; WA; AB; BC
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Discussion | 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.) |
Ovary hairiness in some Salix sitchensis populations varies from uniformly hairy to glabrescent, with intermediates with patchy or streaky hairiness. All three variations can occur together and do not seem to indicate hybridization. Both Salix sitchensis and S. scouleriana have similar variants with leaves having very densely curly hairs on abaxial surfaces [S. sitchensis forma coulteri (Andersson) Jepson and S. scouleriana forma poikila (C. K. Schneider) C. K. Schneider]. Plants resembling S. drummondiana but with similar indumentum probably are hybrids with S. alaxensis (see 84. S. drummondiana). The coulteri taxon resembles S. delnortensis in having stipules with adaxial surfaces glabrous and very sparsely glandular toward the base, densely hairy abaxially, and with gland-dotted margins; its branchlets have wavy to crinkly hairs. The possible hybrid origin of S. delnortensis needs study (R. D. Dorn 2000). Hybrids: Salix sitchensis forms natural hybrids with S. alaxensis var. longistylis and S. melanopsis. Hybridization with S. geyeriana reported by J. K. Henry (1915) is not based on convincing specimens. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 7, p. 34. | FNA vol. 7, p. 159. |
Parent taxa | Salicaceae > Salix > subg. Protitea > sect. Humboldtianae | Salicaceae > Salix > subg. Vetrix > sect. Sitchenses |
Sibling taxa | ||
Synonyms | S. coulteri, S. sitchensis var. parvifolia | |
Name authority | Willdenow | Sanson ex Bongard: Mém. Acad. Imp. Sci. St.-Pétersbourg, Sér. 6, Sci. Math. 2: 162. (1832) |
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