dioecious

Dioecious describes organisms that have separate male and female individuals. The term is used in both botany and zoology to denote a clear separation of the two sexes across individuals rather than within a single organism.

In plants, a dioecious species has distinct male plants that produce only male flowers and pollen, and female plants that produce only female flowers and, after pollination, fruits containing seeds. This is in contrast to monoecious species, where a single plant bears both male and female flowers, and to hermaphroditic flowers that contain both male and female reproductive structures in one bloom. Dioecy can affect reproduction, population structure, and genetic diversity, and the sex of individuals can be fixed genetically or influenced by environmental factors in some species.

In animals, dioecy means that individuals are distinctly male or female and cannot change sex. Humans, many other mammals, birds, and some insects are dioecious. The ecological and evolutionary implications of dioecy include considerations of mate finding, dispersal, and parental investment, as well as the potential for sexual dimorphism driven by differential selection on the two sexes.

Examples of dioecious plants include date palm (Phoenix dactylifera), kiwifruit (Actinidia deliciosa), holly (Ilex), and ginkgo (Ginkgo biloba). In horticulture and agriculture, dioecy influences breeding programs and cultivation practices, as fruit production depends on the presence of both male and female individuals in proximity or on the use of specialized cultivars.