BOX ELDER 



BOX ELDER. ASH-LEAVED MAPLE 



Acer negtindo. 



Distributed across the continent, abundant throughout the Mis- 

 sissippi valley along banks of streams and borders of swamps. 

 Prefers a deep rich soil and attains the height of fifty to seventy feet. 

 The trunk often divides near the ground into a number of stout wide- 

 spreading branches. Grows rapidly. 



Bark. Pale gray or light brown, deeply cleft into broad ridges, 

 scaly. Branchlets pale green, later are bright green, sometimes 

 purplish with a bloom, lenticular for several years. 



Wood. Cream-white ; light, soft, close-grained, not strong ; used 

 for wooden ware and paper pulp. Sp. gr., 0.4328 ; weight of cu. ft., 

 26.97 Ibs. 



Winter Buds. Terminal buds acute, an eighth of an inch long. 

 Lateral buds obtuse. The inner scales enlarge when spring growth 

 begins and often become an inch long before they fall. 



Leaves. Opposite, compound, of three to five leaflets. Leaflets 

 two to four inches long, two to three inches broad, oval or ovate, 

 rounded or wedge-shaped at. base, coarsely and irregularly serrate, 

 acute. The odd leaflet is oftener three-lobed than simple ; midrib 

 and veins conspicuous. They come out of the bud with under sur- 

 face coated with tomentum, when full grown are more or less downy, 

 bright light green above, paler beneath. In autumn they turn a 

 pale yellow. Petioles long, slender, two or three inches long, bases 

 enlarged and often hairy. Stipules caducous. 



Flowers. April, before the leaves, dioecious, yellow green ; 

 staminate flowers in clusters on slender hairy pedicels one and a half 

 to two inches long. Pistillate flowers in narrow drooping racemes. 



Calyx. Yellow green ; staminate flowers campanulate, five-lobed, 

 hairy. Pistillate flowers smaller, five-parted ; disk rudimentary. 



Corolla. Wanting. 



Stamens. Four to six, exserted ; filaments slender, hairy ; an- 

 thers linear, connective pointed. 



Pistil. Ovary hairy, borne on disk, partly enclosed by calyx, 

 two-celled, wing-margined. Styles separate at base in% two stig- 

 matic lobes. 



Fruit. Maple keys, full size in early summer. Borne in droop- 

 ing racemes, pedicels one to two inches long. Key an inch and a 

 half to two inches long, nutlets diverging, wings straight or incurved. 

 September. Seed half an inch long. Cotyledons, thin, narrow. 



85 



