A. rubrum is a deciduous
tree. The leaves are green in color and turned into red in autumn but can also
become yellow or orange on some of leaves. They are typically 5 – 10 cm (2 – 4
in) long and same as wide, with 3 – 5 palmate lobes with a serrated margin. The
sinuses are typically narrow, but the leaves can display important variation.
The top side of the leaves are light green and the down side is whitish and can
be either sea-blue or hairy. The leaf stalks are up to 10 cm (4 in) long and
usually red in color.
The flowers of Red Maple are
appear in spring generally coming before the new leaves. The flowers usually
unisexual, with male and female flowers blooming in individual sessile
clusters, although sometimes they are also bisexual. The considered Polygamodioecious
by itself that meaning some flowers individuals are male, some are female, and
some flowers are monoecious. For the Climate condition, the Red Maple tree
sometimes can change from male to female or male to hermaphroditic, or
hermaphroditic to female. The tree usually start blooming when it grow about 8
years old but it significantly varies between tree to tree some trees star
blooming when 4 years old. The flowers are red in color, with 5 small petals
and 5 lobed calyx borne in hanging clusters, usually at the twig tips. They are
lineal to oblong in shape with pubescent. The feminine flowers have one pistil
formed from two fused carpels with a glabrous superior ovary and two long
styles that protrude beyond the calyx. The staminate flowers contain 4 – 12
stamens, sometime with 8.
