Salix cascadensis |
Salix laevigata |
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Cascade willow, Cascades willow |
polished willow, red willow |
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Habit | Plants 0.03–0.1 m, forming clones by rhizomes. | Trees, 2–15 m. Stems: branches flexible to highly brittle at base, gray-brown to yellow-brown, glabrous or villous; branchlets yellow-brown or red-brown, glabrous, densely villous, velvety, or pilose, nodes hairy. |
Stems | erect or trailing; branches yellow-brown or gray-brown, (sometimes weakly glaucous), glabrous; branchlets yellow-green or yellow-brown, glabrous or puberulent. |
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Leaves | (marcescent); stipules absent; petiole 1.5–5 mm; largest medial blade usually amphistomatous, narrowly elliptic or elliptic, 9–26 × 3.8–7.5 mm, 2.4–4.3 times as long as wide, base cuneate, margins flat, entire, ciliate, apex acute, acuminate, or convex, abaxial surface glabrous or pilose, hairs wavy, adaxial slightly glossy, glabrous or pilose; proximal blade margins entire; juvenile blade glabrous or sparsely villous abaxially. |
stipules rudimentary grading into foliaceous or absent on early ones, usually foliaceous on late ones, apex acute, acuminate, rounded or convex; petiole (shallowly or deeply grooved adaxially, margins sometimes touching, sometimes with basilaminar glands, thickening), 3.5–18 mm, pubescent to glabrescent adaxially; largest medial blade lorate, narrowly oblong, narrowly elliptic, lanceolate, or obovate, 53–190 × 11–35 mm, 2.8–9 times as long as wide, base convex, subcordate, rounded, or cuneate, margins crenate, entire, or finely serrulate, apex acuminate, acute, or caudate, abaxial surface glabrous or pubescent, hairs spreading, white and/or ferruginous, adaxial highly or slightly glossy, glabrous or pubescent, midrib sometimes villous; proximal blade margins entire; juvenile blade glabrous or moderately densely long-silky to pilose abaxially, hairs white and/or ferruginous. |
Staminate flowers | abaxial nectary (0–)0.2–0.6 mm, adaxial nectary oblong or square, 0.4–1.2 mm, nectaries distinct; filaments distinct or basally connate; anthers ellipsoid, 0.3–0.6 mm. |
abaxial nectary 0.4–0.6 mm, adaxial nectary oblong, square, or ovate, 0.3–0.6 mm, nectaries distinct; stamens 3–7; filaments (sometimes basally connate), hairy on proximal 1/2 or basally; anthers 0.4–0.6 mm. |
Pistillate flowers | adaxial nectary oblong or square, 0.5–1.2 mm, longer than stipe; stipe 0–0.6 m; ovary pyriform, usually densely villous, beak abruptly tapering to or slightly bulged below styles; ovules 6–10 per ovary; styles 0.3–1 mm; stigmas slenderly cylindrical, 0.28–0.39–0.56 mm. |
adaxial nectary square, 0.2–0.6 mm; stipe 1.4–2.8 mm; ovary pyriform, obturbinate, or ellipsoidal, beak slightly bulged below styles; ovules 12–24 per ovary; styles 0.1–0.2 mm; stigmas 0.2–0.23–0.28 mm. |
Capsules | 3.5–5 mm. |
3–5.5 mm. |
Catkins | staminate (20–50 flowers), 12.5–26.5 × 5.5–9 mm, flowering branchlet 1–11 mm; pistillate moderately densely to loosely flowered, (15–35(–43) flowers), stout or subglobose, 10–23(–30 in fruit) × 5–8 mm, flowering branchlet 2–9 mm; floral bract brown, 1.6–2.6 mm, apex rounded, entire, abaxially sparsely hairy or ciliate, hairs wavy or straight. |
staminate 31–83 × 7–13 mm, flowering branchlet 2–26 mm; pistillate 28–79 × 6–11 mm, flowering branchlet 3–14 mm; floral bract 1.6–3.4 mm, apex rounded or acute, irregularly toothed or entire, abaxially sparsely to moderately densely hairy proximally or throughout, hairs wavy; pistillate bract deciduous after flowering. |
Salix cascadensis |
Salix laevigata |
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Phenology | Flowering early Jul-early Aug. | Flowering (Dec-)Feb or mid Apr-early Jun. |
Habitat | Mesic to dry rocky slopes, ridges, high subalpine and alpine tundra | Riparian forests along streams, seepage areas, springs, subalkaline or brackish lakeshores, canyons, ditches |
Elevation | 2200-3900 m (7200-12800 ft) | 0-2200 m (0-7200 ft) |
Distribution |
CO; UT; WA; WY; BC
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AZ; CA; NV; OR; UT; Mexico (Baja California, Baja California Sur)
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Discussion | The morphological variability of Salix cascadensis is not well understood. Typically, it has leaves that are narrow, sharply pointed, and glaucous abaxially, catkins 15–43-flowered, dark brown floral bracts, and ovaries very densely hairy. Specimens with leaves not glaucous abaxially, catkins relatively few-flowered, and ovaries either sparsely hairy throughout, hairy only on beaks, or hairy in streaks, may be hybrids but the glabrous ovaried S. cascadensis var. thompsonii shows no obvious signs of hybridization. Hybrids: Salix cascadensis is suspected to hybridize with S. barclayi. Salix cascadensis × S. rotundifolia var. dodgeana resembles the former in its narrow, acute to acuminate leaves and the latter in leaves not glaucous abaxially, tawny floral bracts, relatively short catkins, and glabrous ovaries. The catkins are intermediate in being 6–7-flowered. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Hybrids: Salix laevigata forms natural hybrids with S. gooddingii. Related Species: Salix humboldtiana Willdenow: Humboldt willow is not known to occur in the flora area. 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. 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.) |
Source | FNA vol. 7, p. 82. | FNA vol. 7, p. 34. |
Parent taxa | Salicaceae > Salix > subg. Chamaetia > sect. Diplodictyae | Salicaceae > Salix > subg. Protitea > sect. Humboldtianae |
Sibling taxa | ||
Synonyms | S. tenera, S. cascadensis var. thompsonii | S. bonplandiana var. laevigata, S. laevigata var. angustifolia, S. laevigata var. araquipa, S. laevigata var. congesta |
Name authority | Cockerell: Muhlenbergia 3: 9. (1907) | Bebb: Amer. Naturalist 8: 202. (1874) |
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