SAPINDACEA, 
SILVA OF NORTH AMERICA. 9 
ACER NIGRUM. 
Black Maple. 
LEAVES 8 to 5-lobed, deeply cordate, the basal sinus often closed, pubescent below, 
stipulate. Branchlets light orange-colored. 
Acer nigrum, Michaux, f. Hist. Arb. Am. ii. 238, t. 16 
(1812). — Pursh, Fl. Am. Sept. i. 266. — Poiret, La- 
marck Dict. Suppl. v. 669. — Nuttall, Gen. i. 253. — De 
Candolle, Prodr. i. 595. — Sprengel, Syst. ii. 225.— Don, 
Gen. Syst. i. 650. — Spach, Hist. Vég. iii. 104; Ann. Sci. 
Nat. sér. 2, ii. 170. — Dietrich, Syn. ii. 1282. —C. Koch, 
Dendr. i. 5382. — Bailey, Popular Gardening, iii. 24; Bot. 
Gazette, xiii. 213.— Koehne, Deutsche Dendr. 382. — 
Acer saccharinum, var. glaucum, Pax, Engler Bot. Jahrb. 
vii. 242 (in part) (1886).— Wesmael, Bull. Soc. Bot. 
Belg. xxix. 61 (Gen. Acer) (in part). 
Acer Saccharum, var. nigrum, Britton, Trans. N. Y. Acad. 
Sci. ix. 9 (1889). — Trelease, Rep. Missouri Bot. Gard. 
v. 96, t. 7.— Robinson, Gray Syn. Fl. N. Am. i. pt. i. 
439. 
Acer barbatum, var. nigrum, Sargent, Garden and Forest, 
Britton & Brown, Jil. FV. ii. 398, £. 2376. 
Acer saccharinum, 8 nigrum, Torrey & Gray, Fl. N. 
Am. i. 248 (1838). — Gray, Man. 80. — Torrey, Fl. N.Y. 
i. 136.— Loudon, Arb. Brit. i. 411. — Sargent, Forest 
Trees N. Am. 10th Census U. S. ix. 49.— Watson & 
Coulter, Gray’s Man. ed. 6, 117. — Dippel, Handb. Laub- 
holzk. ii. 439, £. 206. 
iv. 148 (1891) ; Silva N. Am. ii. 99 (in part). — Beal, 
Rep. State Board Agric. Michigan, xxxiii. 148, t. 1, f. 
8-10, t. 2, f. 46, t. 3 (The Sugar Maple of Central 
Michigan). 
Acer palmifolium, var. concolor, Schwerin, Gartenflora, 
xlii. 457, f. 6, 7 (1893). 
The Black Maple is a tree, sometimes eighty feet in height, with a trunk frequently three feet in 
diameter, and stout spreading or often erect branches. The bark of young trees is close, smooth, and 
generally rather lighter colored than that of the Sugar Maple of the same age, but on old trunks it becomes 
deeply furrowed and often nearly black. The branchlets are stout, marked by oblong pale lenticels, 
and when they first appear are orange-green in color and pilose, with scattered pale caducous hairs ; 
during their first year they are orange or orange-brown and lustrous, and in the following season become 
pale gray-brown and lose their lustre. The winter-buds are sessile, ovate, acute, and an eighth of an inch 
long or less, with dark red-brown scales coated on the outer surface with hoary pubescence and often 
slightly ciliate on the margins. The leaves are cordate, with a broad basal sinus usually more or less 
closed by the approximation or imbrication of the basal lobes, generally three or occasionally five-lobed 
with acute or acuminate lobes undulately narrowed from broad shallow sinuses or rarely furnished with 
short spreading lateral lobes; when they unfold they are coated below with thick hoary tomentum and 
clothed above with caducous pale hairs, and at maturity they are thick and firm in texture, dull green 
on the upper surface, yellow-green and soft-pubescent particularly along the yellow vems on the lower 
surface, and five or six inches across, with drooping sides; they are often conspicuously pendant, and 
are borne on stout tomentose or pubescent sometimes ultimately glabrous petioles from three to five 
inches long, much dilated at the base and frequently nearly inclosing the buds, and in falling leave 
narrow scars which almost encircle the branchlet, and are furnished in their axils with tufts of long pale 
hairs. The stipules are triangular and dentate or foliaceous, sessile or stipitate, oblong, acute, tomentose 
or pubescent, sometimes slightly lobed, and frequently an inch and a half in length.” In the autumn 
1 The Black Maple differs from the other forms of the Sugar 
Maple in the light orange-brown color of the young branchlets, 
those of all the others being bright red-brown and very lustrous, 
in the presence of stipules and in important leaf characters; and as 
these appear constant throughout the region occupied by this tree 
it can perhaps best be separated from the other members of the 
Sugar Maple group and treated as a species. 
2 Gray, Am. Nat. vi. 767; vii. 422. — Sargent, Garden and For- 
est, iv. 148, f£. 27. 
On the fertile branches found in herbaria the stipules are not 
