Salix humboldtiana |
Salix daphnoides |
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Humboldt's willow |
daphne willow, violet willow |
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Stems | branches red-brown, strongly glaucous (losing glaucescence in age but remaining so at nodes), glabrescent; branchlets yellow-brown, (not glaucous, except in age), usually glabrescent, sometimes sparsely or moderately densely tomentose. |
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Leaves | stipules (often adnate to petioles), usually rudimentary on early ones, late ones lanceolate to ovate, apex acuminate or acute, often adnate to petiole; petiole shallowly grooved, or convex to flat adaxially, 5–18 mm, tomentose to glabrescent adaxially; largest medial blade oblong, lorate, narrowly elliptic, or elliptic, 50–96(–120) × 1–35(–40) mm, base cuneate to concave, margins slightly revolute, serrate to crenate, apex acuminate, abaxial surface glaucous, glabrescent or midrib sparsely tomentose, hairs (white, sometimes also ferruginous), spreading, straight, long or short, adaxial slightly glossy, (midrib sparsely tomentose or throughout); proximal blade margins entire, closely gland-dotted; juvenile leaves green, sparsely to moderately densely long-silky abaxially, hairs white, sometimes some ferruginous. |
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Staminate flowers | adaxial nectary narrowly oblong to flask-shaped, 0.5–1 mm; filaments distinct or connate basally; anthers purple turning yellow, short- to long-cylindrical or ellipsoid, 0.5–0.7 mm. |
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Pistillate flowers | adaxial nectary oblong to square, 0.4–0.9 mm; ovary pyriform, beak gradually tapering to styles; ovules 4–6 per ovary; styles 0.6–1.5 mm. |
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Capsules | 3.2–4.4 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 before or just before leaves emerge; staminate stout, 30–47 × 9–20 mm, flowering branchlet 0–1.2 mm; pistillate densely flowered, stout, 20–50 mm, flowering branchlet ca. 1.5 mm; floral bract dark brown or bicolor, 2.8–3 mm, apex acute to convex, moderately densely hairy throughout, hairs straight. |
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2n | = 38. |
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Salix humboldtiana |
Salix daphnoides |
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Phenology | Flowering late Mar-early May. | |
Habitat | Disturbed habitats | |
Elevation | 60-600 m (200-2000 ft) | |
Distribution |
Mexico to central Chile |
MA; MN; AB; ON; QC; SK; Europe [Introduced in North America] |
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 daphnoides is cultivated on prairies for windbreaks and elsewhere for its ornamental catkins. Its stipules are unusual in being attached to petiole bases, even when rudimentary. As the petiole dilates around reproductive buds, the stipules become adnate to it. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 7, p. 34. | FNA vol. 7, p. 161. |
Parent taxa | Salicaceae > Salix > subg. Protitea > sect. Humboldtianae | Salicaceae > Salix > subg. Vetrix > sect. Daphnella |
Sibling taxa | ||
Name authority | Willdenow | Villars: Prosp. Hist. Pl. Dauphiné, 51. (1779) |
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