The sugar maple tree can be either male, female or both. The trees are either dioecious, producing separate male and female flowers on the same tree, or monoecious, with male and female flowers on different trees.
Determining whether a given sugar maple tree is male or female can be done using the flowers. The male flowers of the sugar maple are 3 to 4 inches long and are a yellowish-green with five teeth and exerted stamens. The female flowers are 1 to 2 inches long and are produced either in drooping umbels or on branched corymbs. Both male and female flowers are hairy and bloom in mid- to late spring.