418 SALICACE^E. (WILLOW FAMILY.) 



20. S. Uva-tTrsi, Pursh. (BEARBEBRY WILLOW.) Leaves elliptical 

 and pointed, or obovate and obtuse, tapering at the base, slightly toothed, strong- 

 ly veined, smooth and shining above, rather glaucous beneath ; catkins mostly 

 lateral, oblong-cylindrical ; ovary smooth, stalked ; style distinct ; stamen single ; 

 scales oblanceolate, entire, black, covered with long silky hairs. (S. Cutleri, Tucker- 

 man.) Alpine summits of the White Mountains, New Hampshire, and Adi- 

 rondack Mountains, New York. A very small, almost prostrate shrub, known 

 at once by the monandrous flowers. (S. retusa, L., with which this species has 

 been confounded, is a plant of the Southern Alps, having the catkins issuing 

 from the terminal buds, with smooth, notched scales, and two stamens.) 



21. S. repeals, L. (CREEPING WILLOW.) Leaves lanceolate, pointed, 

 when young obovate and obtuse, irregularly repand-toothed, smooth and green 

 above, covered beneath when young with long and shining deciduous hairs, at maturity 

 smooth and glaucous ; catkins ovoid, short ; ovary densely silky, stalked ; style 

 very distinct ; stamens 2 - 3 ; gland sometimes double ; scales obovate, obtuse, 

 clothed with long hairs. (S. fusca, Smith.) Moist alpine ravines of the White 

 Mountains, New Hampshire, and high northward. : Whole plant, when young, 

 of a glossy, satiny lustre ; the leaves at length becoming quite smooth, with a 

 white and prominent midrib, and slightly elevated veins. (Eu.) 



22. S. herfoacea, L. (HERB-LIKE WILLOW.) Leaves roundish-oval, 

 heart-shaped, notched at the apex, serrate, smooth and shining, with reticulated 

 veins ; catkins issuing from the terminal buds, small and few-flowered ; ovary ses- 

 sile, smooth; scales smooth, ciliate. Alpine summits of the White Mountains 

 of New Hampshire, and high northward. A very small herb-like species, the 

 stems seldom rising above an inch or two from the ground. (Eu.) 



2. POPUL.US, Tourn. POPLAR. ASPEN. 



Bracts (scales) of the catkins irregularly cut-lobcd at the apex. Flowers from 

 a cup-shaped disk which is obliquely lengthened in front. Stamens 8 - 30, or 

 more : filaments distinct. Stigmas elongated. Trees, with usually broad and 

 more or less heart-shaped or ovate-toothed leaves, and mostly angular branches. 

 Buds invested with imbricated scales, covered with resinous varnish. Aments 

 long and drooping, appearing before the leaves. (The ancient name, called 

 Arbor Populi, because it was used to decorate the public walks, or on account of 

 the constant agitation of the leaves by every impulse.) 



1. P. tremuloides, Michx. (AMERICAN ASPEN.) Leaves rsandish- 

 hean -shaped, with a short sharp point, and s?naJ/ somewhat regular teeth, smooth on 

 both sides, with downy margins ; scales cut into 3-4 deep linear divisions, fringed 

 with long hairs. Woods ; common. Tree 20 - 50 high, with smooth green- 

 ish-white bark. Stalk of the leaf long, slender, and laterally compressed, which 

 accounts for the continual agitation of the foliage by the slightest breeze. 



2. P, graiididcaitfita, Michx. (LARGE-TOOTHED ASPEN.) Leave* 

 roundish-ovate, with large and irregular sinuate teeth, when yoang densely covered 

 with white silky wool, at length smooth both sides ; scales cut into 5-6 unequal 

 small divisions, slightly fringed. Woods, New England to Penn., Wisconsin, 

 and northward. -A rather larger tree than the last, with a sruoothish gray bark. 



