The flowers of Couroupita guianensis are
pollinated by female bees that collect hood pollen to feed to
their larvae. At the same time, fertile pollen from the ring is
deposited on their head and back from where it is transferred
to the stigma of subsequent flowers visited. Lecythidaceae are
mostly self-incompatible so ring pollen usually has to be carried
from a flower of one tree to a flower of another tree.
Middle right: ring pollen in monads.
Lower left: hood pollen in tetrads.
Lower right: rough exine of hood pollen.
Other frames show pollen of Lecythis pisonis
which is not morphologically differentiated.