Column (botany)

The column, or technically the gynostemium, is a reproductive structure in the center of an orchid flower (also in the Family Aristolochiaceae). It is derived from the fusion of both male and female parts (stamens and pistil) into a single organ that both releases pollen and also receives it (from another individual) for fertilization. Unlike almost all other flowering plants, the single male anther at the tip of the column produces pollen that is not free and powdery but held in waxy masses of two, four or six pellets called pollinia. The transfer of pollinia from one flower to another, though highly efficient, is often reliant upon one particular species of insect and it can be catastrophic for the population if its pollinator disappears from the community.