Color, Appearance, or Grain of Wood. Heartwood brownish, sapwood nearly white, close-grained, compact structure. Structural Qualities of Wood. Soft, light, weak. Representative Uses of Wood. Paper-pulp and occasionally woodenware. Weight of Seasoned Wood in Pounds per Cubic Foot. 28. Modulus of Elasticity. 1,360,000. Modulus of Rupture. 10,200. Remarks. The several "poplars" are much prized for paper-pulp. The quaking aspen (_P. tremuloides_) has long leaf-stalks flattened vertically to the leaf-surface, so that leaves tremble in slight winds. [p084] COTTONWOOD. _Populus deltoides Marsh._ _Populus monilifera Ait._ Nomenclature. (Sudworth.) Cottonwood (local and common name). Carolina Poplar (Pa., Miss., La., N. M., Ind., Ohio). Yellow Cottonwood (Ark., Ia., Neb.). Big Cottonwood (Miss., Neb.). Whitewood (Ia.). Cotton Tree (N. Y.). Necklace Poplar (Tex., Col.). Broadleaved Cottonwood (Colo.). Locality. Canada to Florida, westward intermittently to Rocky Mountains. Features of Tree. Seventy-five to one hundred feet in height, four to five feet in diameter, occasionally much larger. Long catkins distribute cotton-like fibres. Color, Appearance, or Grain of Wood. Thin heartwood, dark brown, sapwood nearly white, close-grained, compact structure. Structural Qualities of Wood. Light, soft, weak, liable to warp, difficult to season. Representative Uses of Wood. Greatly valued in manufacture of paper-pulp, also packing-boxes, fence-boards, fuel. Weight of Seasoned Wood in Pounds per Cubic Foot. 24. Modulus of Elasticity. 1,400,000. Modulus of Rupture. 10,900. Remarks. _Monilifera_ is from the Latin _monolinum_, a necklace, and _fero_, to bear, and refers to the long necklace or catkin. [p085] BLACK COTTONWOOD. _Populus trichocarpa Torr. and Gr._ Nomenclature. (Sudworth.) Black Cottonwood (Oreg., Cal.). Balsam Cottonwood, Balm (Oreg.). Cottonwood (Oreg., Cal.). Balm Cottonwood (Cal.). Locality. Pacific coast region, Alaska to California. Features of Tree. A large tree sometimes one hundred and fifty feet in height and four to six feet in diameter. Color, Appearance, or Grain of Wood. Heartwood light dull brown, sapwood nearly white, compact structure. Structural Qualities of Wood. Light, soft, weak. Representative Uses of Wood. Staves, woodenware (local). Weight of Seasoned Wood in Pounds per Cubic Foot. 23. Modulus of Elasticity. 1,580,000. Modulus of Rupture. 8400. Remarks. Largest deciduous tree of Puget Sound district (Sargent). [p086] CUCUMBER TREE. _Magnolia acuminata Linn._ Nomenclature. (Sudworth.) Cucumber Tree (R. I., Mass., N. Y., Pa., N. C., S. C., Ala., Miss., La., Ark., Ky., W. Va., Ohio, Ind., Ill.). Mountain Magnolia (Miss., Ky.). Black Lin, Cucumber (W. Va.). Magnolia (Ark.). Locality. New York to Illinois, southward through Kentucky and Tennessee to Gulf (intermittently).