138 



TREES OF NORTH AMERICA 



in their second year. Bark pale, 3'-4' thick, deeply divided by wide fissures into narrow 

 ridges. 



Distribution. In moist fertile soil near springs, at the base of high chalky bluffs of 



Fig. 132 



Nueces Canon of the upper Nueces River, Uvalde County, growing with Salix nigra var. 

 Lindheimeri, Carya pecan, Morus rubra and Ulmus crassifolia, and at Strawn, Palo Pinto 

 County, Texas. 



2. SALIX L. Willow. 



Trees or shrubs, with watery juice, scaly bark, soft wood, slender terete tough branchlets 

 often easily separated at the joints, and winter-buds covered by a single scale of 2 coats, 

 the inner membranaceous, stipular, rarely separable from the outer, inclosing at its base 

 2 minute opposite lateral buds alternate with 2 small scale-like caducous leaves coated 

 with long pale or rufous hairs. Leaves variously folded in the bud, alternate, simple, 

 lanceolate, obovate, rotund or linear, penniveined ; petioles sometimes glandular at 

 the apex, and more or less covering the bud, in falling leaving U-shaped or arcuate 

 elevated leaf-scars displaying the ends of 3 small equidistant fibro- vascular bundles; 

 stipules oblique, serrate, small and deciduous, or foliaceous and often persistent, generally 

 large and conspicuous on vigorous young branches, leaving in falling minute persistent 

 scars. Flowers in sessile or stalked aments, terminal and axillary on leafy branchlets; 

 scales of the ament lanceolate, concave, rotund or obovate, entire or glandular-dentate, 

 of uniform color or dark-colored toward the apex, more or less hairy, deciduous or per- 

 sistent; disk of the flower nectariferous, composed of an anterior and posterior or of a single 

 posterior gland-like body ; stamens 3-1 2 or I or 2, inserted on the base of the scale, with slender 

 filaments free or rarely united and usually light yellow, glabrous, or hairy toward the base, 

 and small ovoid or oblong anthers generally rose-colored before anthesis, becoming orange 

 or purple; ovary sessile or stipitate, conic, obtuse to subulate-rostrate, glandular at the 

 base, glabrous, tomentose or villose, with an abbreviated style divided into 2 short re- 

 curved retuse or 2-parted stigmas; ovules 4-8 on each of the 2 placentas. Fruit an acum- 

 inate 1 -celled capsule separating at maturity into 2 recurved valves. Seeds minute, nar- 

 rowed at the ends, dark chestnut-brown or nearly black; cotyledons oblong. 



Salix inhabits the banks of streams and low moist ground, the alpine summits of moun- 



