Flowers are essential for plants to reproduce. There are a lot of different kinds of flowers, including ones that grow on trees, that have specific characteristics that encourage pollinators to visit them.

Trees cannot go in search of sex partners. They need an agent to transfer pollen, either between the male and female parts of a tree's own flowers, or between the flowers produced by different trees.Bees and other insects, like moths, and even animals inadvertently pollinate as they collect nectar. In Africa, giraffes generously serve as pollinators for the Acacia trees that have blossoms high up.

Pollen Allergies: Blame It On The Wind

Some pollens are simply carried by the wind. It is the wind-borne pollen of trees and grasses, rather than the heavier pollen of flowers on plants, that cause allergic reactions in some people. Most flowers pollinated by birds are unscented because birds actually don't smell well. Flowers with protruding stamens, however, are easily brushed against by birds as they fly from flower to flower.

The Creativity Of Trees Seeking Pollinators

Trees are innovative in their strategies for attracting pollinators. Here are a couple fun facts:

• Hankerchief tree thoughtfully provides large white bracts that guide pollinating moths to its flowers by night.
• The Horse Chestnut tree even has flowers that conveniently change color from yellow to red after pollination. This makes it possible for bees, who see the color red as an unattractive black, to be attracted to only those flowers that are awaiting pollination.