monoicous

Monoicous is a botanical term used to describe a gametophytic individual that bears both male and female reproductive organs. In many bryophytes, such as mosses and liverworts, a monoicous thallus or gametophyte carries archegonia (female organs) and antheridia (male organs) on the same plant, enabling fertilization when water is available to mobilize sperm.

This condition is contrasted with dioicous species, in which male and female plants are separate individuals. The monoicous arrangement is common in various bryophyte lineages and reflects a strategy for sexual reproduction that does not require distant individuals for fertilization, though many species still benefit from cross-fertilization under natural conditions.

The term is primarily used for bryophytes; in vascular plants the analogous situation is usually described as monoecious, meaning both male and female flowers occur on the same plant. Etymologically, monoicous derives from Greek roots meaning “one house,” reflecting the presence of both sexual functions within a single organism.

Related concepts include dioicous, monoecious, and hermaphroditic reproductive systems. In bryophytes, the presence of both archegonia and antheridia on one gametophyte influences breeding biology and patterns of fertilization, particularly in environments where water is a limiting and variable factor.