The Trees of Vermont ITi 



ACERACEAE 



Black Sugar Maple 

 Acer saccharum nigrum (Michx. f.) 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, wnth the leaves ; monoecious ; in nearly sessile, 

 umbel-like corymbs ; about 54 ^^ich long, yellow, on slender, hairy 

 pedicels 2-3 inches long ; calyx campanulate, pilose, 5-lobed ; corolla ; 

 stamens 7-8 ; ovary hairy. 



Fruit. — Ripens in autumn ; glabrous, paired samaras, clustered 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 fur- 

 rowed and sometimes almost black on the trunk. 



Wood. — Hard, heavy, strong, close-grained, creamy white, with 

 thin, lighter colored sapwood. 



Distribution. — Lake Champlain valley. Occasional. 



Habitat. — Low, moist, rich soil of river-bottoms. 



Notes. — This tree has long been a puzzle to botanists. Li leaf 

 characters it differs considerably from the sugar maple, but resembles 

 it in fruit characters, general habit and in sugar production. As in- 

 dicated in the key, the leaf is less deeply lobed, and is minutely hairy 

 on the low^er face; it may be hairy also along the leaf stalk. It is 

 thicker and more leathery in texture and usually is heart-shape at the 

 base, the rounded basal lobes sometimes overlapping. This black sugar 

 maple should not be confused with specimens of the ordinary sugar 

 maple having darker bark. Sugar-makers often term such trees "black 

 maples." The bark of this black sugar maple generally is dark, but 

 the leaf characters must be appealed to in its recognition. 



