However, given that functional protandric dioecy
has been shown to occur in P.
In Angiosperms the return to unisporangiate flowers together with monoeicy and dioecy, is most obviously associated with wind pollination.
Ecological constraints on the evolution of breeding systems in seed plants; dioecy and dispersal in gymnosperms.
Table 1 A Family Level Comparison Between the Number and Type of Dioecious Species that have been Studied and those that Exist All dioecy
The literature records a strong association between dioecy and
association between dioecy and outbreeding (Bawa, 1974; Bawa &
Unlike most Ericaceae, Empetreae exhibit a high degree of dioecy
(found elsewhere in Ericaceae only in Epigaea and possibly some Gaultherieae).
Although dioecy has been reported in various species of Pernettya from the Galapagos and Juan Fernandez Islands and temperate Chile/Argentina (Anderson et al.
Dioecy and wind pollination in Pernettya rigida (Ericaceae) of the Juan Fernandez Islands.
Anemophily is often associated with dioecy
in many plant groups (Sporne, 1965).
There are about twice as many monoecious (9%) and dioecious (9%) species in the Juan Fernandez Archipelago as there are in angiosperms as a whole (5% and 4% for monoecy and dioecy, respectively; Richards, 1997).
The highest levels of dioecy among flowering plants are found in oceanic islands (Carlquist, 1974; Richards, 1997).
in Bauhinia resulting from organ suppression.
Ecological constraints on the evolution of breeding systems in seed plants: dioecy
and dispersal in gymnosperms.
The debate over the forces that drive the evolution of dioecy
has created two contending schools of thought: the predominant view, that separation of the sexes has evolved because it reduces inbreeding (which is seen as inherently detrimental), and the less common view, that selection for sexual specialization, i.