Cacao flowers--and the seed pods that result if they are fertilized--grow directly off the trunk of the tree. Botanists call this pattern "cauliflory." Europeans had never seen such a thing, and usually "corrected" drawings of the tree by moving the cacao pods out onto the smaller branches. Scientists theorize that the arrangement of flowers right off the trunk might facilitate pollination by small, moisture-loving insects, especially ants and flies associated with leaf litter.
Scientists are just beginning to understand how wild cacao trees reproduce. Recent studies in plantations indicate that midges, tiny flies that inhabit the damp, shady rain forest, play a crucial role in cacao pollination. The cacao flower, which is about the diameter of a nickel, is complicated in design, and the midge is the only animal that can work its way through the flower.