The term xenogamia refers to the mechanism by which pollination takes place through pollen of the same species but produced from a plant other than the one bearing the egg.
The term xenogamia comes from the Greek ξένος, xenos “guest, foreigner” + -γαμία, gamìa / der. of γαμέω, gameo “marry” /.
Xenogamy therefore also leads to the formation of fruits obtained from xenogamic fertilization. In this case we speak of xenocarpy.
Xenogamia is a form of allogamy, as the gametes come from different individuals.
Thus, in plants there are two types of allogamy or cross-pollination: xenogamy and geitonogamy. In xenogamy, flowers of genetically distinct individuals intervene in pollination, therefore distinct plant gametes.
In geitonogamy, however, pollination occurs with pollen from another flower of the same individual. In this case, therefore, the gametes have the same genetic heritage.