Andromonoecy is a breeding system of plant species in which
male and
hermaphrodite flowers are on the same plant.[1] It is a monomorphic
sexual system comparable with
monoecy,
gynomonoecy and
trimonoecy.[2] Andromonoecy is frequent among
genera with
zygomorphic flowers,[3] however it is overall rare and occurs in less than 2% of plant species. Nonetheless the breeding system has gained interest among biologists in the study of sex expression.[4]
Etymology
The word andromonoecious is a combination of andr- (meaning male) and monoecious and was first used in 1877.[5]
Prevalence
Andromonoecy is uncommon and has been estimated to occur in less than 2% of plant species.[4] In angiosperms, it occurs in 1.7% of angiosperms making up around 4000 species in 33 families.[6][7] It is common in the grass subfamily
Panicoideae.[8]
Some authors view andromonoecy as a transitional state from hermaphroditism to monoecy.[11] It has been suggested that andromonoecy evolved from hermaphroditism due to the loss of female structures.[9]
Andromonoecy is also considered an evolutionary step towards
dioecy.[15] If
female flowers are better at producing seeds than hermaphroditic ones, andromonoecy could evolve towards monoecy.[16]