ACERACEAE 



Black Maple. Black Sugar Maple 



Acer saccharum nigrum, (Michx. /.) Britt. 

 [Acer nigrum, Michx.] 



HABIT. A stately tree, sometimes reaching a height of 80 

 feet, with a trunk diameter of 2-3 feet; branches stout, forming 

 a broad, rounded, symmetrical crown. 



LEAVES. Opposite, simple, concave, 5-7 inches across, the 

 breadth usually exceeding the length; usually 5-lobed at maturity, 

 the two lower lobes being small, often 'reduced to a mere curve 

 in the outline, the pointed lobes undulate or entire and narrowed 

 from the broad, shallow sinuses ; thick and firm ; glabrous above, 

 downy beneath; petioles stout, usually pendent, tomentose. The 

 sides of the larger leaves often droop giving to the tree an air 

 of depression. 



FLOWERS. May, with the leaves; monoecious; in nearly 

 sessile, umbel-like corymbs ; about J4 inch long, . yellow, on 

 slender, hairy pedicels 2-3 inches long; calyx campanulate, pilose, 

 5-lobed; corolla o; stamens 7-8; ovary hairy. 



FRUIT. Ripens in autumn; glabrous, paired samaras, clus- 

 tered on drooping pedicels; wings set wide apart, but only 

 slightly diverging. 



WINTER-BUDS. Small, ovoid, acute, with dark red- 

 brown, acute scales, hoary-pubescent on the outer surface. 



BARK. Twigs smooth, pale gray; becoming thick, deeply 

 furrowed and sometimes almost black on the trunk. 



WOOD. Hard, heavy, strong, close-grained, creamy white, 

 with thin, lighter colored sapwood. 



DISTRIBUTION. Lower Peninsula, south-eastern por- 

 tion. 



HABITAT. Prefers low, moist, rich soil of river-bottoms, 

 but does well on gravelly soils and uplands. 



NOTES. Very variable. A very good shade tree because 

 of its dense foliage. It is claimed by some that the finest grades 

 of maple sugar are made from the sap of this tree. 

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