2. Acer saccharìnum Linnæus. Silver Maple. Soft Maple. White Maple. [Plate 112.] Medium sized trees; bark of small trees smooth and gray, becoming on old trees reddish-brown, and freely splitting into thin scales; branchlets light to reddish-brown and generally turning upward at their tips; leaves generally about 1 dm. long, generally somewhat cordate at the base, sometimes truncate, deeply 3-lobed, each of the lateral lobes with an additional lobe below, margins of all of the lobes more or less irregular or even lobed, the two principal sinuses generally show a tendency to close, leaves hairy beneath when young, glabrous above and below at maturity and very glaucous beneath; flowers appear in March or April in the axils of the leaves of the previous year, the staminate and pistillate in separate clusters on the same or different trees; fruit on pedicels 1.5-6 cm. long, maturing in the spring or early summer, green, densely hairy while young and remaining more or less hairy at maturity, 4-7 cm. long, wings 1-2 cm. wide.
Distribution.—New Brunswick to Florida, west to South Dakota and south to Texas. Locally frequent to very common in all parts of Indiana. This species is always found in wet or moist places, and in the lower Wabash bottoms in low overflow lands or in or about old sloughs it often forms the principal stand. It is more frequently associated with black willow, white elm, red birch, sycamore, etc.
Remarks.—The silver maple has been used extensively for shade tree planting. The branches are very brittle, and ice storms sometimes break off so many branches that the tree may be badly injured. The shade trees of this species are in many parts of the state being killed by scale insects, and for this reason it should not be used. On account of its rapid growth it has also been much used for windbreaks but this practice should be discouraged and better species used.
ACER SACCHARINUM Linnæus. Silver Maple. (× 1/2.)
3. Acer rùbrum Linnæus. Red Maple. Soft Maple. Swamp Maple. [Plate 113.] Medium to large sized trees; bark of small trees smooth and gray, becoming dark brown on old trees, somewhat furrowed and scaly; branchlets smooth and reddish; twigs generally smooth but sometimes hairy, becoming glabrous by autumn; leaves 5-12 cm. long, 3-5 lobed, more or less cordate at the base, sometimes truncate or rounded, sinuses acute, those of 3-lobed leaves generally wider angled than those of 5-lobed ones, the lobes more or less irregularly serrate or dentate, hairy while young, glabrous above and more or less hairy beneath at maturity, glaucous beneath; flowering period March or April; flowers red or reddish, in the axils of the leaves of the previous year, the staminate and pistillate in separate clusters on the same or different trees; fruit maturing late in spring, on pedicels 3-8 cm. long, generally red, sometimes green, glabrous at maturity, rarely somewhat pubescent, 1.5-3.5 cm. long.
Distribution.—Newfoundland to Florida, west to Minnesota and south to Texas. It is found in all parts of Indiana. Its preferred habitat is that of low ground about lakes, swamps, along streams and in the "flats" in the southeast part of the State. Throughout its range in Indiana where it is found in low ground, it is in places rich in organic matter, except in the "flats" of the southern part of the State where it grows in a hard clay soil with sweet gum, red birch, etc. In contrast the silver maple is generally found growing in wet places with little organic matter; especially is this true in the lower Wabash bottoms. The red maple grows also on high ground. In the northern part of the State it is only an occasional tree of gravelly ridges or on high ground about lakes or along streams. In the southern part of the State it is a local to a frequent tree in most parts of the "knob" area where it is associated with white oak, black oak, black gum, etc. It is also an occasional tree on the top of bluffs and cliffs.