The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

Humboldt's willow

rock willow

Habit Plants 0.2–1.5 m. Stems erect; branches brownish or red-brown, (dull), glabrous, long-silky, or villous to glabrescent; branchlets yellow-brown or gray-brown, long-silky, pilose, or moderately densely villous.
Leaves

stipules absent or rudimentary;

petiole (shallowly to deeply grooved adaxially), 2–8 mm, (with 2 spherical glands distally, dark brown, sometimes basilaminar, sparsely pubescent or glabrous adaxially);

largest medial blade hypostomatous, (veins strongly impressed-reticulate), broadly elliptic, subcircular, or obovate, 18–67 × 10–40 mm, 1.1–2.3 times as long as wide, base rounded, convex, or subcordate, margins strongly revolute, crenate or subentire, apex rounded, convex, retuse, or toothed, abaxial surface sparsely to densely villous or long-silky, veins often with long, straight hairs, adaxial slightly glossy, glabrous or sparsely long-silky;

proximal blade margins entire or crenate;

juvenile blade (yellowish green), abaxially very densely long-silky.

Staminate flowers

abaxial nectary 0.6–0.8 mm, adaxial nectary narrowly oblong, 0.5–1.2 mm, nectaries connate and shallowly cup-shaped, or distinct;

filaments distinct, hairy on proximal 1/2;

anthers ellipsoid or globose, 0.3–0.5 mm.

Pistillate flowers

abaxial nectary (0–)0.8–0.9 mm, adaxial nectary oblong, ovate, or narrowly oblong to almost filiform, 0.7–1.4 mm, shorter to longer than stipe, nectaries distinct or connate and cup-shaped;

stipe 0.4–1.2 mm;

ovary pyriform or obnapiform, densely short-silky, hairs cylindrical, beak abruptly tapering to styles;

ovules 13–15 per ovary;

styles connate 1/2 their lengths to almost distinct, 0.2–0.4 mm;

stigmas flat, abaxially non-papillate with rounded tip, slenderly cylindrical, or 2 plump lobes, 0.2–0.28–0.36 mm.

Capsules

3–5 mm.

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.

Catkins

staminate 13–48 × 4–6.5(–8) mm, flowering branchlet 3–31(–50) mm;

pistillate densely flowered, slender or stout, 18–56 × 4–10 mm, flowering branchlet 3–27(–40) mm;

floral bract tawny, 0.8–1.6 mm, apex rounded, entire, abaxially densely hairy, hairs straight.

2n

= 38.

Salix humboldtiana

Salix vestita

Phenology Flowering mid Jun-late Jul.
Habitat Moist to dry open forests and rocky streamsides, in upper montane and subalpine zones, rarely alpine
Elevation 0-2400 m (0-7900 ft)
Distribution
from USDA
Mexico to central Chile
[BONAP county map]
from FNA
MT; OR; WA; AB; BC; MB; NL; NS; NU; ON; QC; Asia (China [Xinjiang], Mongolia, Russia, e, c Siberia)
[WildflowerSearch map]
[BONAP county map]
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 vestita is an ancient amphiberingian species. Its distribution includes a series of isolated, disjunct populations in Central Siberia, the northern Rocky Mountains, the west coast of Hudson Bay, and the northeastern arctic and subarctic. Occurrence in Nunavut is on Akpatok Island in Ungava Bay and on the Belcher Islands in Hudson Bay. It may be extirpated in Washington.

The flowering and vegetative branchlets sometimes have relatively short internodes. In subsequent years, branches have the appearance of short shoots similar to those in Alnus. Short shoots do not appear on all branches or in all years. The formation of short shoots may be related to adverse growing conditions.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 7, p. 34. FNA vol. 7, p. 64.
Parent taxa Salicaceae > Salix > subg. Protitea > sect. Humboldtianae Salicaceae > Salix > subg. Chamaetia > sect. Chamaetia
Sibling taxa
S. alaxensis, S. alba, S. amygdaloides, S. arbusculoides, S. arctica, S. arctophila, S. argyrocarpa, S. arizonica, S. athabascensis, S. atrocinerea, S. aurita, S. babylonica, S. ballii, S. barclayi, S. barrattiana, S. bebbiana, S. bonplandiana, S. boothii, S. brachycarpa, S. breweri, S. calcicola, S. candida, S. caprea, S. caroliniana, S. cascadensis, S. chamissonis, S. chlorolepis, S. cinerea, S. columbiana, S. commutata, S. cordata, S. daphnoides, S. delnortensis, S. discolor, S. drummondiana, S. eastwoodiae, S. elaeagnos, S. eriocephala, S. euxina, S. exigua, S. famelica, S. farriae, S. floridana, S. fuscescens, S. geyeriana, S. glauca, S. gooddingii, S. hastata, S. herbacea, S. hookeriana, S. humilis, S. interior, S. irrorata, S. jejuna, S. jepsonii, S. laevigata, S. lasiandra, S. lasiolepis, S. lemmonii, S. ligulifolia, S. lucida, S. lutea, S. maccalliana, S. melanopsis, S. monochroma, S. monticola, S. myricoides, S. myrsinifolia, S. myrtillifolia, S. nigra, S. niphoclada, S. nivalis, S. nummularia, S. orestera, S. ovalifolia, S. pedicellaris, S. pellita, S. pentandra, S. petiolaris, S. petrophila, S. phlebophylla, S. planifolia, S. polaris, S. prolixa, S. pseudomonticola, S. pseudomyrsinites, S. pulchra, S. purpurea, S. pyrifolia, S. raupii, S. reticulata, S. richardsonii, S. rotundifolia, S. scouleriana, S. sericea, S. serissima, S. sessilifolia, S. setchelliana, S. silicicola, S. sitchensis, S. sphenophylla, S. stolonifera, S. taxifolia, S. thurberi, S. tracyi, S. triandra, S. turnorii, S. tweedyi, S. tyrrellii, S. uva-ursi, S. vestita, S. viminalis, S. wolfii, S. ×fragilis, S. ×jesupii, S. ×pendulina, S. ×sepulcralis, S. ×smithiana
S. alaxensis, S. alba, S. amygdaloides, S. arbusculoides, S. arctica, S. arctophila, S. argyrocarpa, S. arizonica, S. athabascensis, S. atrocinerea, S. aurita, S. babylonica, S. ballii, S. barclayi, S. barrattiana, S. bebbiana, S. bonplandiana, S. boothii, S. brachycarpa, S. breweri, S. calcicola, S. candida, S. caprea, S. caroliniana, S. cascadensis, S. chamissonis, S. chlorolepis, S. cinerea, S. columbiana, S. commutata, S. cordata, S. daphnoides, S. delnortensis, S. discolor, S. drummondiana, S. eastwoodiae, S. elaeagnos, S. eriocephala, S. euxina, S. exigua, S. famelica, S. farriae, S. floridana, S. fuscescens, S. geyeriana, S. glauca, S. gooddingii, S. hastata, S. herbacea, S. hookeriana, S. humboldtiana, S. humilis, S. interior, S. irrorata, S. jejuna, S. jepsonii, S. laevigata, S. lasiandra, S. lasiolepis, S. lemmonii, S. ligulifolia, S. lucida, S. lutea, S. maccalliana, S. melanopsis, S. monochroma, S. monticola, S. myricoides, S. myrsinifolia, S. myrtillifolia, S. nigra, S. niphoclada, S. nivalis, S. nummularia, S. orestera, S. ovalifolia, S. pedicellaris, S. pellita, S. pentandra, S. petiolaris, S. petrophila, S. phlebophylla, S. planifolia, S. polaris, S. prolixa, S. pseudomonticola, S. pseudomyrsinites, S. pulchra, S. purpurea, S. pyrifolia, S. raupii, S. reticulata, S. richardsonii, S. rotundifolia, S. scouleriana, S. sericea, S. serissima, S. sessilifolia, S. setchelliana, S. silicicola, S. sitchensis, S. sphenophylla, S. stolonifera, S. taxifolia, S. thurberi, S. tracyi, S. triandra, S. turnorii, S. tweedyi, S. tyrrellii, S. uva-ursi, S. viminalis, S. wolfii, S. ×fragilis, S. ×jesupii, S. ×pendulina, S. ×sepulcralis, S. ×smithiana
Synonyms S. leiolepis, S. vestita subsp. leiolepis, S. vestita var. psilophylla
Name authority Willdenow Pursh: Fl. Amer. Sept. 2: 610. (1813)
Web links