Acer saccharum

Tree to 30 m tall, trunk to 1.8 m in diameter Leaves: opposite, stalked, bright green above, lighter green beneath, 7.5 to 20 cm long and wide, usually five-lobed, few-toothed. Leaves turn yellow to scarlet red in the fall. Flowers: either male or female, found on the same (monoecious) or different (dioecious) plants, borne in few-flowered clusters, greensih yellow. Fruit: winged (samara), paired, 3 - 3.5 cm long, with wings spread to a 60-degree angle. Bark: dark gray to grayish brown, smooth when young, becoming deeply furrowed. Twigs: smooth, changing from green to orangish or reddish brown to gray. Terminal buds: reddish brown, 5 - 8 mm long, conical, pointed, with slightly hairy scales.

Similar species: Acer platanoides is easy to distinguish from Acer saccharum and Acer nigrum by its milky sap exuded from the leaf stalk, broader and more blunt terminal buds, and samaras with wings spread to nearly 180 degrees. Similarities between A. saccharum and A. nigrum are so striking, some view them as the same species. Acer nigrum has very dark bark that looks corrugated and leaves that are mostly three-lobed, dark green, drooping at the sides, velvet-like underneath, with stipules at the base of the stalk. Acer saccharum var. saccharum is highly variable with gray bark, mostly five-lobed leaves with few hairs beneath, and margins that do not curl under. Acer saccharum var. schneckii has long, shaggy hairs on the lower leaf surface and leaf stalk, and the margin curls under.

Flowering: April to mid May

Habitat and ecology: Undisturbed woods, well-drained uplands, and lowland but not swampy areas.

Occurence in the Chicago region: native

Notes: Maple syrup is made from the sap of A. saccharum in very early spring. To make one liter of syrup, 30.25 liters of sap are needed. The wood is very hard and durable, making it a desirable material for furniture, cabinets, tool handles, musical instruments, and flooring. This is the state tree of Wisconsin.

Etymology: Acer is derived from a Latin word meaning sharp, which refers to the hardness of the wood. Saccharum is the botanical name for the genus sugarcane, which comes from the Greek word saccharon, meaning "a sweet juice."

Author: The Morton Arboretum

Climax tree to 40 m; bark medium-gray, becoming roughened with loose-edged plates; lvs flat, about as wide as long, usually glabrous beneath except for a few tufts of hairs in the vein-axils, (3)5-lobed with rounded sinuses, the lobes usually bearing a few large sharp teeth, the central lobe usually with nearly parallel sides to a pair of large teeth at about mid-length; fls in umbels from the terminal or uppermost lateral buds, appearing as the lf-buds open, drooping on slender, hairy pedicels to 8 cm; cal gamosepalous, 2.5-6 mm, ±hirsute; pet none; disk extrastaminal; ovary and fr glabrous; mericarps of the fr 2.5-4 cm, the seed- bearing basal parts diverging at right angles to the pedicel, the wings curved forward, divergent at an angle of 120Рor less; 2n=26. Rich to fairly dry woods, especially in calcareous soils; N.S. and N.B. to Minn. and e. S.D., s. to N.J., Del., w. Va., n. Ga., Tenn., and Mo. (Saccharodendron s.; Acer saccharophorum) Plants intermediate toward A. barbatum, occurring along the s. boundary of our range, have been called var. schneckii Rehder, or var. regelii (Pax) Rehder, the latter name however based on a specimen of A. barbatum. Spp. 2-4 often treated as parts of a single sp.

Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.

©The New York Botanical Garden. All rights reserved. Used by permission.

From Flora of Indiana (1940) by Charles C. Deam

A frequent to common tree in all parts of the state. It is absent in the "flats" and on the crests of the ridges in the unglaciated area. It is usually associated with beech or in some of our northern woods the beech is replaced by basswood, red oak, and white ash. The species is very variable in leaf outline and in the pubescence of the petiole and the lower surface of the leaves. Several forms based upon these characters have been named. The sugar maple in Indiana has the lower surface of the leaves glaucous while in the northern range of its distribution it has the lower surface of the leaves green. To distinguish the two forms, Sargent (Bot. Gaz. 67: 233. 1919) named the glaucous form var. glaucum. [Variety rugelii ...] is a form with 3-lobed leaves that is infrequent throughout our area.

......

Indiana Coefficient of Conservatism: C = 4

Wetland Indicator Status: FACU

Diagnostic Traits: Leaves simple, palmately lobed and veined, the sinuses of principal lobes entire; petioles with watery sap; flowers with inconspicuous petals; fruits up to 3.5 cm, curved so that wings lie almost parallel to each other.

Recent classifications assigned Indiana populations to two varieties: saccharum and schneckii. The latter has soft pubescence on the lower leaf surface. It is rare and mostly limited to southwestern Indiana.

Deam (1932): The sugar maple has been and will continue to be one of the most important trees of the state. In its mass distribution in Indiana it ranks not lower than third. In the quality and uses of its wood it is equalled or excelled only by the oak, ash, and hickory. When compared with white oak it is a little lighter but 30 per cent stronger and 53 per cent stiffer. The best grade of the annual cut of maple is worked into flooring which is shipped to all parts of the world. It is much used in the manufacture of furniture and baskets, and ranks third in use for veneer and hard wood distillation, and as a fuel wood is excelled only by hickory. Since pioneer times the sap of this tree has been made into syrup and sugar and their manufacture now forms a valuable industry. On an average it takes 3 to 4 gallons of sap to make a pound of sugar, and an average size tree will annually yield about 3 to 4 pounds of sugar.

The sugar maple on account of its slow growth has not been used much in reforestation. It is tolerant of shade, can adapt itself to almost all kinds of soil, thrives either in a pure or mixed stand, and is practically free from injury of insects and diseases. It has been extensively used as a shade tree. When grown in the open it almost invariably assumes a symmetrical oval form, and the autumnal coloration of its foliage is rarely surpassed by any of our trees. Where a large tree is desired for street or ornamental planting the sugar maple can safely be recommended in many locations.