Pollinium


A pollinium is a coherent mass of pollen grains in a plant that are the product of only one anther, but are transferred, during pollination, as a single unit. This is regularly seen in plants such as orchids and many species of milkweeds. Usage of the term differs: in some orchids two masses of pollen are well attached to one another, but in other orchids there are two halves each of which is sometimes referred to as a pollinium.
Most orchids have waxy pollinia. These are connected to one or two elongate stipes, which in turn are attached to a sticky viscidium, a disc-shaped structure that sticks to a visiting insect.
Some orchid genera have mealy pollinia. These are tapering into a caudicle, attached to the viscidium. They extend into the middle section of the column.
The pollinarium is a collective term that means either the complete set of pollinia from all the anthers of a flower, as in Asclepiadoideae, in Asclepiadoideae, a pair of pollinia and the parts that connect them, or in orchids, a pair of pollinia with two viscidia and the other connecting parts.