Strangler Figs

Strangler figs (Ficus) begin life from a small seed deposited by a bird, fruit bat, or other animal resting on the branches of a canopy tree. At first it is a harmless little epiphyte (an air plant such as lipstick plants). Soon it begins to send its branches upward and its roots downward. From that moment on, the giant tree on which the strangler lives is doomed. Quickly, the strangler's roots compete with the host tree for water and nutrients. They have an extraordinary ability to fuse and form a mesh around the host tree, which eventually dies from being deprived of sunlight and nutrients. In its place will stand a giant fig tree, upon which will occur one of the most complex partnerships innature.
      Strangler figs produce three kinds of very small flowers that may be found in varying combinations lining the inner surface of a hollow, ovoid pseudo-fruit called figs: male flowers producing only pollen; female flowers with long styles and fertile ovaries; and gall flowers with short styles and infertile ovaries. The narrow openings of the figs attract female wasps, which, loaded with pollen, will enter and try to lay their eggs. If a wasp entered a "gall fig" containing male and gall flowers, she will lay her eggs in each of the ovaries of the gall flowers. If the wasp she enters a fig with only female flowers, she will try to deposit her eggs on the ovaries but will fail because the styles are too long for her ovipositor to reach them. On the other hand, these wasps do brush pollen onto the fertile ovaries, which then set seeds. Meanwhile, in the gall flowers, the wasp's offspring emerge. Inside the fig, the small, wingless male waspswill copulate with the winged females, then die, never having left the fig. At this time the male flowers ripen and shed pollen onto the young female wasps, which exit to search for a new place to lay their eggs. (If there are birds swarming over a fig, that's a sure sign the wasps are emerging from their hideaways.) After a while, the fruits will ripen, turning from green to red, and become a delicious feast for hungry birds and mammals. The animals will then pass the fertilized seeds undamaged through their intestines, thus completing the cycle.

Original URL: http://archive.fieldmuseum.org/vanishing_treasures/V_SFigs.htm