Similar to those of Ohio Buckeye (_A. glabra_). Weight of Seasoned Wood in Pounds per Cubic Foot. 26.64. Modulus of Elasticity. Modulus of Rupture. Remarks. [p099] [Illustration: PLATE 21. SWEET GUM (_Liquidambar styraciflua_).] GUM. (_Liquidambar, Nyssa_.) This name is applied to two unrelated American trees--the Sweet or Red Gum (_Liquidambar styraciflua_), a member of the witch-hazel family, and the Sour or Black Gum (_Nyssa sylvatica_), which is one of the dogwoods. The woods afforded by these two trees are also distinct from one another, although both are referred to by the one name, gum. The softer Sweet Gum figures in carpentry. Selected pieces so resemble black walnut as to be cut into veneers and made up into furniture. Sour Gum is harder, it splits with difficulty, and is fitted for small work and implements, such as wagon-hubs and tool-handles. Both woods are close-and often cross-grained, besides being strong, heavy, tough, and difficult to season. [Illustration: SWEET GUM (_Liquidambar styraciflua_).] The Sweet Gum tree is characterized by rough, round balls, resembling those of the sycamore, by pointed star-like leaves, suggesting those of the sugar maple, and by corky ridges on the bark of younger branches. These latter cause the bark to resemble alligator-skin and give rise to the name alligator-wood. _Liquidambar_ refers to gums excreted by the tree and sometimes used in medicine. The Sour Gum bears ovoid bluish-black sour drupes, or fruit containing single roughened seeds. The thick oval leaves are dark green above and dull or hairy below. The foliage of both species becomes brilliant in autumn. [p100] SWEET GUM. _Liquidambar styraciflua Linn._ Nomenclature. (Sudworth.) Sweet Gum (local and common name). Liquidambar (R. I., N. Y., Del., N. J., Pa., La., Tex., Ohio, Ill.). Red Gum (Va., Ala., Miss., Tex., La.). Gum, Gum Tree (Va., S. C., La.). Alligatorwood, Blisted (N. J.). Locality. Connecticut to Florida, westward intermittently to Illinois and Texas, Mexico. Greatest development in basin of Mississippi River. Features of Tree. Eighty to one hundred feet or more in height, three to five feet in diameter. Tall straight trunk, corky ridges frequent on branches. Star-shaped leaves turn to brilliant scarlet in autumn, round balls on long stems. Color, Appearance, or Grain of Wood. Heartwood rich brown suggesting black walnut, sapwood nearly white, close-grained, compact structure. Structural Qualities of Wood. Heavy, rather soft, strong, stiff, not durable when exposed,[55] shrinks and warps badly in seasoning, receives high polish. Representative Uses of Wood. Veneers, cabinet-work, substitute for black walnut, shingles, clapboards, paving-blocks, wooden plates. Weight of Seasoned Wood in Pounds per Cubic Foot. 37 (U. S. Forestry Div.).[56] 36. Modulus of Elasticity. 1,700,000 (average of 118 tests by U. S. Forestry Div.).[56] 1,220,000.