Salix humboldtiana |
Salix bonplandiana |
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Humboldt's willow |
Bonpland willow, Bonpland's willow, red willow |
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Habit | Trees, 1–13 m. Stems: branches yellow-brown to red-brown, glabrous; branchlets yellowish, streaked with red or red-brown, glabrous or puberulent, nodes hairy. | |
Leaves | (marcescent), stipules absent or rudimentary on early ones, foliaceous on late ones, apex rounded, convex, or acute; petiole (rarely with spherical glands distally), 4–16 mm, puberulent or pubescent to glabrescent adaxially; largest medial blade lorate to narrowly lanceolate, 58–155 × 7–27 mm, 4.5–10.7 times as long as wide, base cuneate to convex, margins serrulate to crenulate or entire, apex acuminate to acute, abaxial surface glabrous or glabrescent, hairs appressed, adaxial dull or slightly glossy, glabrous or pilose; proximal blade margins entire; juvenile blade glabrous, puberulent, pilose, or sparsely long-silky abaxially, hairs white. |
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Staminate flowers | abaxial nectary 0.2–0.6 mm, adaxial nectary oblong, square, or ovate, 0.2–0.6 mm, nectaries distinct or connate and cup-shaped; stamens 3–7; filaments hairy basally; anthers 0.3–0.5 mm. |
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Pistillate flowers | adaxial nectary square to oblong, 0.3–0.6 mm; stipe 0.4–2.4 mm; ovary pyriform to obturbinate, beak slightly bulged below or tapering to styles; ovules 8–18 per ovary; styles 0.2–0.3 mm; stigmas (sometimes slenderly cylindrical), 0.18–0.27–0.32 mm. |
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Capsules | 3–6 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 | (usually flowering throughout season and axillary, sessile), staminate 24–131 × 3–10 mm, flowering branchlet 0–12 mm; pistillate (densely to loosely flowered), 24–47 × 6–12 mm, flowering branchlet 0–10 mm; floral bract 0.6–2.2 mm, apex rounded to convex, irregularly toothed or entire, abaxially sparsely to moderately densely hairy proximally, hairs irregularly curly; pistillate bract persistent after flowering. |
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2n | = 38. |
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Salix humboldtiana |
Salix bonplandiana |
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Phenology | Flowering Feb–Apr and throughout year. | |
Habitat | Riparian forests, along streams, dry washes | |
Elevation | 700-2000 m (2300-6600 ft) | |
Distribution |
Mexico to central Chile |
AZ; Mexico (Baja California, Chiapas, Chihuahua, Distrito Federal, Durango, Guanajuato, Guerrero, Hidalgo, Jalisco, Michoacán, Morelos, Nuevo León, Oaxaca, Puebla, Querétaro, Sonora, Tlaxcala, Veracruz, Zacatecas); Central America (Guatemala)
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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.) |
Salix bonplandiana and S. laevigata are closely related and are sometimes treated as varieties (R. D. Dorn 1994). Their ranges overlap in Arizona and in northern Baja California, Mexico. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 7, p. 34. | FNA vol. 7, p. 33. |
Parent taxa | Salicaceae > Salix > subg. Protitea > sect. Humboldtianae | Salicaceae > Salix > subg. Protitea > sect. Humboldtianae |
Sibling taxa | ||
Synonyms | S. bonplandiana var. toumeyi | |
Name authority | Willdenow | Kunth: in A. von Humboldt et al., Nov. Gen. Sp. 2(qto.): 24: plates 101, 102. (1817) |
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