This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol1", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
Salix phylicifolia L. Sp. PI. 1016. 1753.
A shrub 1°-10° high, much branched, the twigs glabrous, dark purple-green, sometimes glaucous. Leaves oblong, lanceolate or elliptic, acute or obtuse at the apex, minutely repand-crenulate or entire, narrowed at the base, bright green and shining above, pale and glaucous beneath, 1' - 3' long, 1/2'-1' wide; petioles 3"-8" long; stipules minute, fugacious, or wanting; aments sessile, dense, oblong-cylindric, the staminate l' or less long, the pistillate 1'-2' long in fruit; bracts villous, persistent; stamens 2; filaments glabrous; style rather longer than the stigmas; capsule conic, acute, pubescent or tomentose, 2i" long, much longer than its pedicel.
Swamps, Labrador to Alaska and the mountains of Maine, New Hampshire and Vermont. Europe. Summer.
Salix chlorophylla Anders., does not appear to be specifically distinct.
Salix obtusata Fernald, Rhodora 9: 223. 1907.
A shrub 1 1/2°-3° high, with smooth brown shining twigs. Leaves oblong to oblong-orbicular, thin, rounded at the apex, obtuse or subcordate at the base, 3/4'-2" long, 1 1/4' wide or less, closely dentate, somewhat pubescent beneath when young, glabrous when mature, the petioles 3"-6" long, slender, the small cordate stipules persistent; aments sessile, borne on twigs of the previous season, the pistillate 10" long or less, 3"-4" thick; bracts obovate, obtuse, villous; capsule conic, glabrous, about 1 1/2" long; gland very short; style not longer than the stigmas.
Gravelly shores, Quebec. Summer.
Salix Uva-ursi Pursh, Fl. Am. Sept. 610. 1814.
A depressed or prostrate glabrous shrub, the terete brown branches 6'-12' long, diffuse from a deep central root. Leaves obovate or elliptic, obtuse or acute at the apex, narrowed at the base, crenulate-denticulate, 4"-10" long, 2"-5" wide, prominently veined, deep green and shining above, pale beneath; petioles 1"-2" long; aments on short leafy branches, dense, about ¥ long in flower, the pistillate 1-2' long in fruit; bracts persistent, obovate, obtuse, densely silky; stamens usually solitary, rarely 2; filaments glabrous; style short; capsule ovoid-conic, acute, glabrous, very short-pedicelled.
Labrador and Hudson Bay to Alaska, south to the summits of the mountains of New York and New England. May-June.
Salix myrtillifolia Anders., of high boreal regions, differs in having nearly erect branches and larger leaves.
Salix herbacea L. Sp. PI. 1018. 1753.
A depressed matted shrub, with very slender angled twigs 1'-6' long, the youngest foliage somewhat pubescent. Mature leaves glabrous, suborbicular, rounded or retuse at the apex, cordate or rounded at the base, thin, crenulate-denticulate all around, finely reticulate-veined, bright green and shining on both sides, 5"-10" in diameter; petioles very slender, 2"-4" long; aments terminating 2-leaved branchlets, 4-10-flowered, 2"-4" long; bracts obovate, obtuse, persistent, glabrous or nearly so; stamens 2; filaments glabrous; style rather longer than the 2-cleft stigmas; capsule narrowly conic, glabrous, nearly sessile.
Labrador and Quebec, through arctic America, and on the White Mountains of New Hampshire and Mt. Katahdin, Maine. Also in Europe and Asia. Summer.