Monocyclanthus is a monotypic genus of flowering plants in the family Annonaceae containing the single species Monocyclanthus vignei.

[2] It is native to Ghana and Liberia.

It is a rare plant of the understory of wet evergreen forest habitat.

[3] It is distinguished from plants in the genus, Uvaria, by the single whorl of petals being valvate, and from Isolona, by both the carpels and the petals being free.

[3] It is threatened by ecosystem conversion and degradation, from mining, quarrying, logging and wood-harvesting.