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Humboldt's willow

Bonpland willow, Bonpland's willow, red willow

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.

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.

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.

Capsules

3–6 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

(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.

2n

= 38.

Salix humboldtiana

Salix bonplandiana

Phenology Flowering Feb–Apr and throughout year.
Habitat Riparian forests, along streams, dry washes
Elevation 700-2000 m (2300-6600 ft)
Distribution
from USDA
Mexico to central Chile
[BONAP county map]
from FNA
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)
[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 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
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. 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. vestita, S. viminalis, S. wolfii, S. ×fragilis, S. ×jesupii, S. ×pendulina, S. ×sepulcralis, S. ×smithiana
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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