<kuid:453099:100289> Sugar Maple - 32M

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Sugar Maple is a species of maple native to the hardwood forests of northeastern North America, from Nova Scotia west to southern Ontario, and south to Georgia and Texas. Sugar maple is best known for its bright fall foliage and for being the primary source of maple syrup.

Sugar Maple is a deciduous tree normally reaching heights of 25–35 m (82–115 ft) tall,[3][4] and exceptionally up to 45 m (148 ft). A 10-year-old tree is typically about 5 m (16 ft) tall.

The leaves are deciduous, up to 20 cm (7.9 in) long and equally wide with five palmate lobes. The basal lobes are relatively small, while the upper lobes are larger and deeply notched. In contrast with the angular notching of the Silver Maple, however, the notches tend to be rounded at their interior. The fall color is often spectacular, ranging from bright yellow through orange to fluorescent red-orange. Sugar maples also have a tendency to color unevenly in fall. In some trees, all colors above can be seen at the same time. There is also a tendency, as there is also with Red Maples, for certain parts of a mature tree to change color weeks ahead of or behind the remainder of the tree. The leaf buds are pointy and brown colored. The recent years growth twigs are green, and turn dark brown.

The flowers are in corymbs of 5-10 together, yellow-green and without petals; flowering occurs in early spring after 30-55 growing degree days. The fruit is a double samara with two winged seeds, the seeds are globose, 7–10 mm (0.28–0.39 in) diameter, the wing 2–3 cm (0.79–1.2 in) long. The seeds fall from the tree in autumn and remain viable for only a few days.

It is closely related to the Black Maple, which is sometimes included in this species but sometimes separated as Acer nigrum. The western American Bigtooth Maple (Acer grandidentatum) is also treated as a variety or subspecies of Sugar Maple by some botanists.

The Sugar Maple is also often confused with the Norway Maple, though they are not closely related within the genus. The Sugar Maple is most easily identified by clear sap in the leaf petiole (the Norway Maple has white sap), brown sharp-tipped buds (the Norway Maple has blunt green or reddish purple buds), and shaggy bark on older trees (the Norway Maple bark has small grooves). Also, the leaf lobes of the Sugar Maple have a more triangular shape, in contrast to the squarish lobes of the Norway Maple.

A red sugar maple leaf is featured on the flag of Canada. Maple leaves are prominent on the Arms of Canada.

The Sugar Maple is an extremely important species to the ecology of many forests in North America. Pure stands are common, and it is a major component of the northern and central U.S. hardwood forests. In the north, it forms associations of beech-maple and Sugar Maple-Yellow Birch, which is most important beyond the northern limit of beech. Sugar Maple-American Basswood, Sugar Maple-White Ash and Sugar Maple-Ironwood--Red Oak are also common forest associations.

Sugar Maple is among the most shade tolerant of large deciduous trees. Among North American maples its shade tolerance is exceeded only by the Striped Maple, a smaller tree. Like other maples, its shade tolerance is manifested in its ability to germinate and persist under a closed canopy as an understory plant, and respond with rapid growth to the increased light formed by a gap in the canopy. The sugar maple can grow comfortably in any type of soil, except sand.

Sugar Maples engage in hydraulic lift, drawing water from lower soil layers and exuding that water into upper, drier soil layers. This not only benefits the tree itself but also many other plants growing around it.

Human influences have contributed to the decline of the Sugar Maple in many regions. Its role as a species of mature forests has led it to be replaced by more opportunistic species in areas where forests are cut over. The Sugar Maple also exhibits a greater susceptibility to pollution than other species of maple. Acid rain and soil acidification are some of the primary contributing factors to maple decline. Also, the increased use of salt over the last several decades on streets and roads for de-icing purposes has decimated the sugar maple's role as a 'street-front' tree.

In some parts of eastern North America, particularly near urbanized areas, the Sugar Maple is being displaced by the Norway Maple. The Norway Maple is also highly shade tolerant, but is considerably more tolerant of urban conditions resulting in the Sugar Maple's replacement in those areas heavily disturbed by human activities.