Trees that produce flowers are among the most valued of ornamentals. There are even many species of trees growing in the wild that are capable of flowering. Identifying flowering trees is a task best attempted when they're in bloom.
Examining the key features of a flowering tree's flowers--the flowers' size, shape, color, when they bloom, arrangement on the branches and form--will help you identify the species. For example, by looking at the yellow-green, six-petaled tulip-like flowers growing in a tree's upper canopy, you could quickly recognize the species as a yellow poplar.
Often the flowers on different species of trees from the same family resemble each other. In such cases, you need to inspect other features of the tree to determine the species. For example, looking at the leaves, bark, fruit, size of the tree, its form and its habitat can help you identify the tree.
Certain species of flowering trees have both male and female flowers, some on the same tree and others on separate trees. The birches and oaks, for example, have both sexes of flowers on the same tree, with distinct differences between the two. A river birch, for instance, has drooping brown male flowers as long as 3½ inches, while the ½-inch-long green female flowers are not at all showy and emerge near the bases of the leaves.