6. Acer Sàccharum Marsh. Sugar Or Rock Maple. Sugar-Tree

Fig. 2809

Acer saccharum Marsh. Arb. Amer. 4. 1785.

Acer saccharinum Wang. Amer. 36. pl. 2. f. 26. 1787.

Not L. 1753. Acer barbatum Michx. Fl. Bor. Am. 2: 252. 1803.

A large and very valuable tree, with maximum height of 100°-120° and trunk diameter of 21/2°-3 1/2°. Leaves 3'-6' long, dark green above, pale beneath, cordate or truncate at the base, 3-7-lobed, the lobes acuminate, irregularly sinuate, the sinuses rounded; flowers in sessile, lateral or terminal corymbs, greenish yellow, drooping on capillary hairy pedicels, appearing with the leaves; petals none; samaras glabrous, slightly diverging, 1'-1 1/2' long, the wing 3 -5 wide.

In rich woods, Newfoundland to Manitoba, south, especially along the mountains, to Florida and Texas. Its sap is the main source of maple sugar. Wood hard, strong, light reddish-brown; weight per cubic foot 43 lbs. The bird's-eye and curled maple of cabinet makers are varieties. The tree is widely planted for shade and for ornament. Hard, black or sweet maple. April-May.

7. Acer Nigrum Michx. Black Sugar Maple

Fig. 2810

Acer nigrum Michx. f. Hist. Arb. Am. 2: 238. pl. 16. 1810.

Acer saccharinum var. nigrum T. & G. Fl. N. A. 1: 248. 1838.

Acer saccharum var. nigrum Britton, Trans. N. Y. Acad. Sci. 9: 10. 1889.

A tree, nearly or quite as large as the Sugar Maple, with rough, blackish bark. Leaves similar, but green both sides, thicker and generally more or less pubescent beneath, especially along the veins; lobes much broader and shorter, with few undulations or frequently entire, the basal sinus often narrow; samaras slightly more divergent.

Quebec, Ontario and Vermont to northern Alabama, west to South Dakota, Louisiana and Arkansas. Wood resembling that of the preceding species, the sap also yielding much sugar. Black or hard maple. April-May.

8. Acer Glàbrum Torr. Dwarf Or Rocky Mountain Maple

Fig. 2811

Acer glabrum Torr. Ann. Lye. N. Y. 2: 172. 1826. Acer tripartitum Nutt.; T. & G. Fl. N. A. 1: 247. 1838.

A shrub, or small tree, with maximum height of about 350 and trunk diameter of 12'. Leaves 1-3' long, often broader, glabrous on both sides, or puber-ulent when young, 3-5-lobed, the lobes acute or obtusish, sharply serrate, the sinuses acute; flowers yellowish green, in numerous small lateral and terminal sessile corymb-like racemes; pedicels short, glabrous, erect or ascending; samaras glabrous, shining, 9"-15" long, little diverging; wing 4"-6" wide.

Borders of streams and hillsides, northwestern Nebraska to Montana and throughout the Rocky Mountain region, south to Arizona, west to the Sierra Nevada. Wood hard, light brown. Weight per cubic foot 37 lbs. Soft, shrubby or bark-maple. May.