When people think of flowering trees, species with showier flowers, like cherries, magnolias, and redbuds, probably come to mind.  But there are understated flowering trees that are worth a look as well.  For example, the red maple (Acer rubrum), one of our more common trees, is currently flowering. Its name actually derives not only from the red buds and flowers the tree produces in the spring, but also from its red leaf petioles in the summer and its brilliant red foliage in the fall.

The red maple’s flowers are small, but attractive, and are worth closer investigation if you happen to be passing by one of these trees in the next week or two.  Each flower consists of 5 small petals and a 5-lobed calyx (a collection of sepals) borne in hanging clusters, usually at the twig tips. The sex of red maple flowers, however, turns out to be somewhat confusing.  Most sources indicate that a single red maple will produce entirely male (containing stamens only) or entirely female (containing pistols only) flowers, but that both male and female flowers can occasionally be found in a single tree or both male and female parts found in a single flower.  To confuse things a bit more, an individual tree that produces all male flowers one year, can switch and produce all female flowers the year after.  So, what are we looking at here? To the best of my knowledge, the red maple flowers in the top picture below above are male, and consist entirely of stamens.  The flowers in the bottom picture are female, and consist entirely of shorter pistols.

Male red maple (Acer rubrum) flowers. 

Female red maple (Acer rubrum) flowers. 

Although the emergence of maple flowers varies throughout the red maple’s range, on Cape Cod, red maple blooms are in full swing now (early to mid April). Flowers generally appear before the leaves (as is the case in the examples pictured here), which aids in wind-pollination so the leaves don’t interfere with the movement of pollen.