geitonogamous

Geitonogamy is a mode of plant pollination in which pollen is transferred between flowers of the same individual plant. It is distinct from xenogamy, pollination between flowers on different plants, and from autogamy, self-pollination within a single flower. Geitonogamy commonly occurs when pollinators such as bees visit multiple flowers on the same plant, or when floral architecture keeps visitors within a single plant as they forage.

The genetic outcome is selfing, since the pollen donor and the recipient flowers share the same genotype. Geitonogamy can reduce genetic diversity and increase the potential for inbreeding depression, especially in populations with limited opportunities for cross-pollination. Nevertheless, it may provide reproductive assurance when pollinator activity is low or when external pollen donors are scarce. Some species also possess self-incompatibility systems that restrict geitonogamous pollen and thereby limit selfing.

In studies of plant reproductive strategies, geitonogamy is treated as a form of self-pollination with distinctive ecological and evolutionary implications compared with autogamy and xenogamy. Its occurrence helps explain patterns of seed production, genetic structure, and breeding system evolution in various taxa.

See also: xenogamy, autogamy, self-incompatibility, pollination biology.