Similar to no. 2 [Acer saccharum Marshall], and not always sharply distinct; bark darker, thicker, more deeply furrowed; lvs darker and duller above, usually pubescent beneath, commonly with somewhat drooping sides and tip, 5-lobed as in no. 2 or often the lowermost lobes reduced or obsolete, the lobes generally with fewer and shorter, often obtuse or rounded teeth, the central lobe tending to taper from the base. Typically in somewhat moister sites than no. 2, often along streams; s. Que. to s. Minn., s. to L.I., N.J., Del., w. Va., w. N.C., Tenn., and n. Ark., commonest in the midwest. (A. saccharum var. nigrum and var. viride; Saccharodendron n.) Plants intermediate toward no. 4 [Acer barbatum Michx.], occurring chiefly in the s. Appalachians, have been called A. leucoderme Small.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Throughout the state and always associated with the sugar maple. Almost pure stands of the sugar maple, however, may occur with this species absent. When the two are associated, the black maple will usually be found in the moister area. Usually infrequent but locally common. [Variety palmeri, if recognized,] is a form with leaves 3-lobed and is far more common than the species in the northern part of the state.
Indiana Coefficient of Conservatism: C = 6
Wetland Indicator Status: FACU
Diagnostic Traits: Similar to A. saccharum and sometimes difficult to separate from; petioles and lower leaf surface hairy, lobe tips often drooping, and lobes shallow.
Tree 18 - 25 m tall, trunk diameter to 1.2 m Leaves: opposite, stalked (with stipules at base), dark green above, yellowish green beneath, 10 - 16 cm long, 10 - 16 cm wide, three-lobed (sometimes five), few-toothed, velvet-like hairs underneath, drooping at sides. Flowers: either male, female, or bisexual, borne on the same or separate plants (polygamous), yellow, hanging in long-stalked clusters. Fruit: winged (samara), paired, 1.2 - 2.5 cm long, with the angle between wings variable. Bark: gray to black, thin when young, becoming deeply furrowed and appearing corrugated with age. Twigs: orangish green to reddish brown and hairy when young, becoming grayish brown and smooth. Buds: reddish brown, small, egg-shaped, with hairy scales.
Similar species: Acer platanoides is easy to distinguish from Acer nigrum by its milky sap exuded from the leaf stalk, broader and The Morton Arboretume blunt terminal buds, and samaras with wings spread to nearly 180 degrees. Similarities between Acer saccharum and A. nigrum are so striking, some view them as the same species. Acer saccharum most often has five-lobed, non-drooping leaves lacking hairs and stipules.
Flowering: late April to mid May
Habitat and ecology: Common in very rich woods and along waterways.
Occurence in the Chicago region: native
Notes: The sap of A. nigrum is used to make maple syrup, which some think is of better quality than syrup made from A. saccharum sap.
Etymology: Acer is derived from a Latin word meaning sharp, which refers to the hardness of the wood. Nigrum comes from the Latin word for black.