Grows on borders of streams and swamps in low ground. Often confused with and substituted for the more valuable white ash. Pubescens is in allusion to the downy covering of the new twigs (those of white ash usually smooth). Pennsylvanica refers to locality in which it is well developed. [p031] BLUE ASH. _Fraxinus quadrangulata Michx._ Nomenclature. (Sudworth.) Blue Ash (Mich., Ill., Ky., Mo., Ala.). Locality. Central States, Mississippi Valley, Michigan, and southward, cultivated in Pennsylvania. Best in low Wabash Valley. Features of Tree. Fifty to seventy-five feet in height, occasionally higher, one to two feet in diameter. Slender. Blue properties in inner bark, smooth square twigs. Color, Appearance, or Grain of Wood. Heartwood light yellow, streaked with brown, sapwood lighter, close-grained, compact structure satiny. Structural Qualities of Wood. Hard, heavy, brittle, not strong, most durable of ash woods. Representative Uses of Wood. Largely used in floorings, carriage-building, pitchfork-and other tool-handles. Weight of Seasoned Wood in Pounds per Cubic Foot. 44. Modulus of Elasticity. 1,100,000. Modulus of Rupture. 11,500. Remarks. Has no superior among ash woods. Blue Ash pitchfork-handles are very fine. Prefers limestone formations. Inner bark colors water blue, whence name. [p032] BLACK ASH. _Fraxinus nigra Marsh._ _Fraxinus sambucifolia Lam._ Nomenclature. (Sudworth.) Black Ash (local and common name). Water Ash (W. Va., Tenn., Ind.). Swamp Ash (Vt., R. I., N. Y.). Brown Ash (N. H., Tenn.). Hoop Ash (Vt., N. Y., Del., Ohio, Ill., Ind.). Locality. Northern and Northeastern States--Newfoundland to Virginia, westward intermittently to Manitoba and Arkansas. Features of Tree. Seventy to eighty feet in height, one to one and one-half feet in diameter. Leaves resemble those of Elder. A thin tree. Excrescences or knobs frequent on trunk. Dark, almost black, winter buds. Color, Appearance, or Grain of Wood. Heartwood dark brown, sapwood light brown, often nearly white, coarse-grained, compact structure, medullary rays numerous and thin. Structural Qualities of Wood. Separates easily in layers, rather soft and heavy, tough, elastic, not strong or durable when exposed. Representative Uses of Wood. Largely used for interior finish, fencing, barrel-hoops, cabinet-making, splint baskets, chair-bottoms. Weight of Seasoned Wood in Pounds per Cubic Foot. 39. Modulus of Elasticity. 1,230,000. Modulus of Rupture. 11,400. Remarks. Excrescences known as burls; their distorted grain causes them to be prized for veneers. The most northerly of ash-trees; one of the most slender of trees. [p033] GREEN ASH. _Fraxinus lanceolata Borkh._ _Fraxinus viridis Michx. f._ Nomenclature. (Sudworth.) Green Ash (local and common name). Blue Ash (Ark., Iowa). White Ash (Kans., Neb.). Ash (Ark., Iowa). Swamp Ash (Fla., Ala., Tex.).