April — Tree flowers

A red haze on the horizon

In late March the view from my house was suddenly accented by a red haze. Could it be? Yes! The red maple trees were already starting to flower. Springtime tree flowering can happen so subtly that we don’t even notice until the spent flowers begin to fall from the trees. The red flowers of red maples make them more conspicuous than many tree species, which have more muted colors — greenish, whitish, yellowish, reddish brown. By watching the canopy carefully, however, you can detect the change in color and even distinguish different species by the flower color.

Why do so many tree species have such inconspicuous flowers? Most people probably never notice the trees flowering at all – unless they have allergies. And therein lies the clue. There are two primary methods in the plant world for dispersing pollen (the genetic material that fertilizes the female flowers) — wind and animals. Plants that use animals to disperse pollen typically have showy flowers and fragrant scents to attract insects, birds and other animals. As animals move from one flower to another they transport the pollen, a process people are very familiar with. The pollen of those flowers is typically “heavy” so that it stays on the flower until picked up by an animal.

In contrast, plants with wind pollination have very small, very light, and very abundant pollen that easily moves on the wind. Since no animals are involved, these plants have no need for showy flower petals. Most have no petals at all, so the flower consists mostly of the staminate parts — the structures that hold the pollen — and some modified leaves at the base (sepals).

Our condolences to the allergy sufferers — the downpour of pollen dust is soon to come.

Red Maple info at Fairfax County Public Schools’s web page