Salix uva-ursi |
Salix irrorata |
|
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bearberry willow |
blue-stem willow, dewy-stem willow |
|
Habit | Plants 0.01–0.05 m, (dwarf), forming clonal compact mats by layering. | Shrubs, 2–7 m, (multistemmed, sometimes forming clones by stem fragmentation). |
Stems | prostrate, short-trailing; branches red-brown, gray-brown, or yellow-brown, glabrous; branchlets yellow-green or yellow-brown, glabrous or puberulent. |
branches (highly brittle or not at base), red-brown to violet, usually glaucous, glabrous; branchlets yellow-brown, (strongly glaucous or not), glabrous, sparsely velvety, or tomentose. |
Leaves | stipules (sometimes marcescent) absent, rudimentary, or foliaceous on early ones, foliaceous on late ones; petiole (shallowly to deeply grooved adaxially), 2–6.5 mm; largest medial blade (marcescent), amphistomatous or hypostomatous, ovate, broadly obovate, oblanceolate, or elliptic, 4–23 × 3.5–10 mm, 1.7–3.6 times as long as wide, base convex or cuneate, margins flat, serrulate or crenulate, apex convex, acuminate, acute, or retuse, abaxial surface glaucous, usually glabrous (rarely few hairs), adaxial slightly or highly glossy, usually glabrous (rarely a few hairs); proximal blade margins entire or serrate; juvenile blade glabrous, pilose, or puberulent abaxially. |
stipules absent or rudimentary on early ones, foliaceous or rudimentary on late ones, apex acute; petiole convex to flat adaxially, 4–14 mm, velvety adaxially; largest medial blade lorate, narrowly oblong, narrowly elliptic, or narrowly oblanceolate, 47–115 × 8–22 mm, 3.5–7.7 times as long as wide, base cuneate or convex, margins flat to slightly revolute, entire and gland-dotted, serrulate or crenate, apex acuminate, acute, or convex, abaxial surface glaucous, glabrous, sparsely tomentose, or short-silky, hairs wavy, adaxial slightly to highly glossy, glabrous or pilose; proximal blade margins entire or serrulate; juvenile blade yellowish green or reddish, glabrous or sparsely villous abaxially, hairs white. |
Staminate flowers | abaxial nectary absent, adaxial nectary narrowly oblong or oblong, 0.4–0.9 mm; filaments distinct, glabrous; stamens usually 1, rarely 2; anthers ellipsoid or shortly cylindrical, 0.4–0.7 mm. |
adaxial nectary narrowly oblong to oblong, 0.3–0.8 mm; filaments connate less than to more than 1/2 their lengths; anthers yellow or purple turning yellow, ellipsoid or shortly cylindrical, 0.4–0.7 mm. |
Pistillate flowers | abaxial nectary absent, adaxial nectary narrowly oblong or oblong, 0.5–0.8 mm, shorter to longer than stipe; stipe 0.3–1.6 mm; ovary ovoid or pyriform, glabrous, beak gradually tapering to styles; ovules 4–9 per ovary; styles 0.4–1 mm; stigmas flat, abaxially non-papillate with rounded tip, or slenderly cylindrical, 0.1–0.23–0.4 mm. |
adaxial nectary narrowly oblong to oblong, 0.3–0.7 mm; stipe 0.4–1 mm; ovary pyriform, beak slightly bulged below styles; ovules 9–12 per ovary; styles 0.3–0.9 mm; stigmas flat, abaxially non-papillate with rounded tip, 0.15–0.28–0.6 mm. |
Capsules | 3–5 mm. |
3.5–4 mm. |
Catkins | staminate 9–19 × 5–8 mm, flowering branchlet 0.5–9 mm; pistillate densely flowered, slender to subglobose, 11–47(–55 in fruit) × 6–10 mm, flowering branchlet 2–10 mm; floral bract brown, black, tawny, light rose, or bicolor, 1.1–1.8 mm, apex rounded or acute, entire, abaxially sparsely hairy, hairs straight or wavy. |
flowering before or just before leaves emerge; staminate stout or subglobose, 15–34 × 8–22 mm, flowering branchlet 0(–2) mm; pistillate densely flowered, stout or slender, 14–43 × 7–12 mm, flowering branchlet 0–4 mm; floral bract brown or black, 1.3–2.5 mm, apex rounded, abaxially hairy, hairs straight or wavy. |
2n | = 38. |
= 38. |
Salix uva-ursi |
Salix irrorata |
|
Phenology | Flowering mid Jun-early Aug. | Flowering mid Mar-mid May. |
Habitat | Exposed, often dry or moist, calcareous, serpentine, dioritic, and granitic rocks, boulders, gravel, sand on beaches, outcrops, in snowbeds | Streams, wet meadows |
Elevation | 10-1200 m (0-3900 ft) | 1400-3000 m (4600-9800 ft) |
Distribution |
ME; NH; NY; VT; NL; NS; NU; QC; SPM; Greenland
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AZ; CO; NM; WY; Mexico (Baja California, Chihuahua, Coahuila, Durango, Sonora)
|
Discussion | Hybrids: Salix uva-ursi forms natural hybrids with S. herbacea. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Salix irrorata is very closely related to S. lasiolepis. The two are here maintained as separate species primarily because S. irrorata is a diploid and S. lasiolepis a tetraploid, and also because of their largely allopatric ranges (G. W. Argus 2007). Studies of sawflies (Euura Newman) by P. W. Price (pers. comm.) show that the same species of Euura can successfully reproduce on either willow. The only morphological character that separates the two is that in S. irrorata branchlets and branches are very strongly glaucous, whereas in S. lasiolepis they are not glaucous. Some plants have weakly glaucous stems (wax not visible except by polishing or only as sparkling crystals); this may be infraspecific variability or evidence of hybridization. Hybrids: Salix irrorata forms natural hybrids with S. drummondiana, S. geyeriana, and S. lasiolepis var. lasiolepis. Salix irrorata × S. lasiolepis var. lasiolepis: This putative hybrid occurs in Arizona and New Mexico. It is characterized mainly by weakly glaucous branches. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 7, p. 73. | FNA vol. 7, p. 155. |
Parent taxa | Salicaceae > Salix > subg. Chamaetia > sect. Myrtosalix | Salicaceae > Salix > subg. Vetrix > sect. Mexicanae |
Sibling taxa | ||
Synonyms | S. ivigtutiana, S. myrsinites var. parvifolia | |
Name authority | Pursh: Fl. Amer. Sept. 2: 610. (1813) | Andersson: Öfvers. Kongl. Vetensk.-Akad. Förh. 15: 117. (1858) |
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