BOX ELDER 



BOX ELDER. ASH-LEAVED MAPLE 



Acer negiindo. 



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 lbs. 



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 into two stig- 

 matic lobes. 



Frnit. — 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 



