pollinium

A pollinium is a specialized structure found in certain plants, most notably orchids, that consists of a coherent mass of pollen grains. This mass is often attached to a stalk and may bear an adhesive disk. Its primary function is to facilitate pollination by clinging to insects, which then transfer the pollen to other flowers.1

In orchids, the pollen grains are typically bound together by a sticky substance called viscin, forming these masses known as pollinia. These can be mealy or waxlike and are crucial for the orchid's reproductive strategy, often involving complex interactions with specific pollinators. The pollinium, along with its associated structures like the caudicle and viscidium, forms the pollinarium.2