A coherent mass of pollen, as in the milkweed and most orchids.

(pl. pollinia) A general term for aggregations of many pollen grains, which form dispersal units ( Jackson, 1928). Examples: Asclepiadaceae, Orchidaceae. See also: dispersal unit, massula.* Polumbra ( Balme, 1988) A darkened triangular or subcircular area centred on the proximal pole. Example: Retusotriletes distinctus. Comment: The feature appears to be most commonly observed in specimens that have lost a perisporal outer exoexinal layer. See also: hilum.

Mass of pollen grains transported as a unit, as in many Orchidaceae and Apocynaceae.