pollinaria

Pollinaria, plural of pollinarium, are discrete pollen masses produced by certain flowering plants that are transferred as a single unit during pollination. They typically consist of one or more pollen grains aggregated into pollinia and attached to a viscidium (a sticky pad) by a slender stalk or structure. The pollinarium is organized so that a pollinator acquires the pollen mass and then deposits it on the stigma of another flower, facilitating cross-pollination.

Pollinaria are best known from groups such as the Orchidaceae (orchids) and the Apocynaceae subfamily Asclepiadoideae (milkweeds) and related lineages. In these plants, pollen is packaged into cohesive units that can be picked up and then reliably placed onto conspecific stigmas. The viscidium adheres to the pollinator’s body, and the pollinarium may include additional structures that help position the pollen correctly on the next flower.

The use of pollinaria represents a highly specialized pollination strategy. By packaging pollen into units and requiring specific interactions with pollinators, plants can reduce pollen loss and increase the likelihood that pollen is transferred between compatible flowers. This often involves intricate flower morphology and pollinator behavior, with different lineages evolving variations in how pollinaria are produced, carried, and deposited.

In summary, pollinaria are compact, unitized pollen masses associated with certain plant groups, enabling efficient and targeted pollen transfer by pollinators.