Weight of Seasoned Wood in Pounds per Cubic Foot. 30. Modulus of Elasticity. 1,100,000. Modulus of Rupture. 9720. Remarks. Ornamental tree has been introduced into Europe. Said to be one of the most valuable Pacific coast broadleaf woods. [p046] BOXELDER, ASH-LEAVED MAPLE. _Acer negundo Linn._ _Negundo aceroides Moench._ Nomenclature. (Sudworth.) Boxelder, Ash-leaved Maple (local and common name). Red River Maple, Water Ash (Dak.). Cut-leaved Maple (Colo.). Stinking Ash (S. C). Negundo Maple (Ill.). Three-leaved Maple (Fla.). Black Ash (Tenn.). Sugar Ash (Fla.). Locality. Atlantic Ocean westward intermittently to Rocky Mountains, Mexico. Features of Tree. Forty to seventy feet in height, one and one-half to three feet in diameter. Wings to keys are straight or incurved. Leaves sparingly and coarsely toothed, show yellow but little or no red in autumn. Color, Appearance, or Grain of Wood. Thin heartwood, cream-white; sapwood similar; close-grained, compact structure. Structural Qualities of Wood. Light, not strong, soft. Representative Uses of Wood. Woodenware, cooperage, etc., paper-pulp (largely), occasionally interior finish. Weight of Seasoned Wood in Pounds per Cubic Foot. 26. Modulus of Elasticity. 82,000. Modulus of Rupture. 7500. Remarks. A rapid grower. Withstands severe climatic changes. A good tree to plant in naturally treeless sections. Sugar is sometimes obtained from the sap of this species. The "Boxelder" is a true maple. [p047] [Illustration: PLATE 9. WALNUT (_Juglans_). Black Walnut Tree (_Juglans nigra_). Black Walnut Trunk (_Juglans nigra_). Black, White, and English Walnuts. Black Walnut Wood (_Juglans nigra_).] WALNUT. (_Juglans_.) The English or Royal Walnut (_Juglans regia_), a native of Persia, was the only available species of this genus until the introduction of the nearly similar Black Walnut of North America.[29] As oak gave way first to soft woods for construction, so it gave way first to walnut for cabinet purposes. The wood soon became very fashionable, and exorbitant prices were paid for it. Walnut was extremely popular in the United States until about 1880, when oak began to resume its place as the popular cabinet wood. The nuts of the English or Persian walnut are better than those of the American species, but the wood of the latter is superior.