Xenogamy

[Oralee]

Marital - Marriage between people from different backgrounds - especially from foreign lands (or in fiction, from alien worlds); a more extreme/diverse form of heterogamy.

[Botany] - Floral fertilisation by genetically different [pollen].

Origin: From Greek [xenos] (stranger) and gamos (marriage).

[Sommer]

Fertilization of a flower by pollen from a flower on a genetically different plant.

[Tina]

[marriage] with [a foreigner].