=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.
=Remarks.=--The red maple is not abundant enough in Indiana to be of any
economic importance. It grows rapidly and should replace the silver
maple for shade tree planting since its branches are not broken off as
easily by ice storms and it is more resistant to insect attack.
=3a. Acer rubrum= variety =Drummóndii= (Hooker and Arnott) Torrey and
Gray. This variety of the red maple is a form found in the dense swamps
of the lower Wabash Valley. It is distinguished from the type by its
twigs which generally remain more or less hairy until maturity; by the
under surface of the leaves remaining more or less tomentose during the
summer, and by its larger fruit. This variety is known with certainty
only from Little Cypress Swamp in Knox County about 12 miles southwest
of Decker. Here it is a frequent to a common tree associated with
cypress, swell-butt ash, button-bush, sweet gum, etc. All of the trees
of this locality have 5-lobed leaves.
[Illustration: Plate 113.