99 



COTTONWOOD. 

 Poptilus deltoides, Marshall. 



FOBM — A large tree usually oOTu ft. high but may reach a height of more than lOU ft. 

 with a diameter of C feet. Trunk tapering, continuous, sometimes clean for a considerable 

 distance from the ground. Crown usually high and pyramidal. Lower lateral branches 

 hcr}zoDtal, while most of the upper branches are decidedly ascending. 



BABK — On old trunks thick, ashy-gray, roughened by long deep furrows which are usually 

 !„'itudinally parallel, and often connect with one another. Rather thin, smooth, and greenish- 

 low on younger trunks. 



TWIGS — St5ut, usually yellow tinged with green or brown, round or ridged below the buds; 

 covered with large, longitudinally- elongated lenticels; pith white and angular. 



BUDS — Alteriete, large, resinous, glossy, smooth, chestnut-brown, covered with numerous 

 bud siales which are sticky, resinous on the interior and smooth on the exterior. Terminal buds 

 oft'-'n o angled and larger than lateral ones; lateral buds usually divergent and often recurved. 



LEAVES^Alternale, simple, broadly deltoid, truncate to wedge-shaped at base, acuminate at 

 apex, coarsely serrate on margin, 3-5 inches long, thick, deep shining green above, pale 

 green below. I oaf -stalks laterally flattened. 



LEAF-SCABS — Alternate, large, lunate, elevated, depressed on upper margin, sometimes Slobed; 

 with 3 bundle-scars. Stipule-scars dark and conspicuous. 



TLOWEBS — Appear about March or April. Stamlnatc and pistillate flowers occur on different 

 t [ . s. The stamina te are arranged in drooping aments 3-4 inches long and are densely 

 1j> wered; the pistillate, in drooping aments '2h-Zi inches long and sparsely flowered. 



FRUIT — A drooping anient bearing dark green, 3-4-valve<l capsules which contain small 

 seeds surrounded with a mat of long white hairs. Fruiting amenta longer than in the other 

 native species, 8-12 inches. 



WOOD — Diffuse-porous; with very indistinct rays; pores in ^orly wood visible to unaided 

 eyes; beartwood dark brown; sapwood wide and white: wood is soft, warps easily, and is 

 difficult to split. Weighs about 23 lbs. per cubic foot Used for paper pulp, boxes, crates, 

 berry boxes, pails, and tubs. 



DISTINGUISHING CHABACTEBISTICS — The Cottonwood, also known as Carolina Poplar, 

 Cotton Tree, and WhitewooJ may readily be distinguished at any season of the year by its 

 lateral branches whicli ha^e a tendency to ascend like the Lombardy Poplar (Fig. 36), 

 and by its yellowish twigs which often have prominent ridges running down from the leaf- 

 scars. The buds are larger, more :esinous, and often more flattened than those of any other 

 member of this genus; usually divergent and ofli^n incurved. The leaves are vi-ry character- 

 istic since tliey have laterally flattened leaf -stalks, are deltoid in outline, truncate at the 

 base and long-pointed at the ape.x. The pores in the early wood arc visible to the unaided 

 eye while those of the American and Large-toothed Aspens are uot visible. 



RANGE — Quebec and Ontario south to Florida, west to the Rocky Mountains. 



DISTBIBUTION IN PENNSYLVANIA— Natural distribution is very limited. Reported from 

 Presque IeIc. Erie county and from Lancaster county. Ix)cally escaped cultivation. Planted 

 extensively for ornamental purposes and in a few plantations for forestry purposes. 



HABITAT — Pitfers rich moist soil, like banks of streams, borders of lakes, and semi- 

 swamps. 



IMPORTANCE OF THE SFECIES — The Cottonwood is planted extensively as an ornamental 

 tree but as such it has few merits except its rapid growth, rather attractive form in winter, 

 and the pleasant bnlsaniic odor from its coated, young, developing leaves. It is well adapted 

 to wet locations and may be planted where other more valuable trees will not grow. It grows 

 rapidly, and p't-duces an excellent pulp-wood. This tree is known to grow 5 feet in a single 

 year and 40 feet in 10 years. Cuttings taken from trees and placed in the ground grow very 

 readily. When planted in the streets its roots often lift pavements, and clog drains and 

 sewers. Not adapted for street planting. 



