166 



TREES OF NORTH AMERICA 



staminate flower broad and oblique; stamens numerous, with large oblong anthers 

 and short filaments; disk of the pistillate flower cup-shaped, irregularly dentate, 

 inclosing to the middle the long-stalked ovary full and rounded at the apex, with 

 3 broad crenulate lobed stigmas raised on the short branches of the style. Fruit 

 oblong-ovate, thick-walled, acute, 3 or 4-valved, slightly ridged, buff color, ^' long, 

 on slender pedicels ^-f in length and placed rather remotely on the slender gla- 

 brous rachis of the ament. 



A large tree, with wide-spreading branches, stout light orange-colored glabrous 



branchlets, and acute lustrous buds. Bark pale gray-brown, deeply divided into 

 broad flat ridges. 



Distribution. The common Cottonwood in the valley of the Rio Grande of 

 western Texas and New Mexico, and the adjacent parts of Mexico. 



2. SAUX, L. W'illow. 



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, penni- 

 veined; their 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 persistent; 

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

 posterior gland-like body; stamens 3-12 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 ovate or oblong anthers generally rose-colored before 



