197 



ASH-LEAVED MAPLE, or BOX ELDER. 

 Acer Negundo, Linnaeus. 



FORM — A medium-sized tree occasionally attaining a height of 70 ft. with a diameter 

 of 3 feet. Trunk usually short, dividing into stout, sometimes drooping branches which form 

 a deep broad crown. Occasionally an open grown tree possesses a long clean trunli. 



BARK — On branches and young trunks smooth and grayisfl-brown ; that of older ones rather 

 thick, distinctly narrow ridged, and seldom scaly. 



TWIGS — Stout, purplish-greeu or green, sotnetimes smooth, often covered with a whitish 

 bloom and scattered raised lenticels. 



BUDS — Opposite, short-stalked, large, ovoid; the terminal acute and the lateral obtuse; 

 white-woolly, covered by bud-scales, the outer pair usually completely enclosing the inner 

 pair. Collateral buds are common and often distend outer scales. 



LEAVES — Opposite, compound, with 3-5 leafle'ts. Leaflets ovate, coarsely and irregularly 

 serrate, 2-4 inches long and 2-3 inches broad. 



LEAF-SCARS — Opposite, V-shaped, bordered by light colored margin, encircling stem so that 

 adjacent edges of opposite scars meet at a very sharp angle. Bundle-scars usually 3, seldom 

 divided, arranged in a lunate Ime. 



FLOWERS — Appear in April before or with the leaves on the past season's growth. Stami- 

 nate and pistillate occur on different trees, tne former on hairy drooping pedicels, the latter 

 in narrow drooping racemes. 



FRUIT — ^Matures about September but is full grown earlier. Wings of the keys about 1^-2 

 inches long, parallel or incurved, borne in drooping racemes. Fruit-stalks persist far into 

 winter. 



WOOD — Diffuse-porous; light, soft, creamy- .vhile, close-grained, not durable. Used in the 

 manufacture of woodonware, cooperage, wood pulp, and sometimes in cheap furniture. Weighs 

 26.97 lbs. per cubic foot. 



DISTINGUISHING CHARACTERISTICS— The Ash-leaved Maple, also known as Box Elder, 

 is readily distinguished in summer by its opposite, compound leaves with 3 to 5 leaflets and its 

 green branchlets covered with a whitish bloom. The maple keys arranged in drooping racemes 

 are also characteristic. In winter the green branchlets are distinctive together with the large, 

 ovoid, often collateral and downy buds. The leaf-scars encircle the stem and their adjacent 

 edges form a very sharp angle. ^ 



RANGE — Vermont westward to Ontario, south to Florida, Texas, and Mexico. 



DISTRIBUTION IN PENNSYLVANIA— Rare end local. Most abundant in the eastern and 

 southern parts of the State with a few outposts reported in Westmoreland and Allegheny 

 counties. 



HABITAT — Thrives best in moist soil, but also tolerant of drier situations. Commonly found 

 along streams, border of laker, or swamps. Often planted for ornamental purposes on dry 

 locations. 



IMPORTANCE OF THE SPECIES — It is of little commercial importance as a timber tree. 

 It yields a sap from which some maple sugar is made locally. This tree is very attractive as 

 an ornamental tree and is planted extensively as a shade, lavra, road-side and park tree. It 

 grows rapidly and has an attractive form in winter and a dense green foliage in summer. 



