Considerable ffort has been spent documenting correlations between dioecy and various ecological and morphological traits for the purpose of testing hypotheses about conditions that favor dioecy. The data analyzed in these studies, with few exceptions, come from local floras, within which it was possible to contrast he subsets of dioecious and nondioecious taxa with regard to the traits in ques...

Surveys of plant breeding systems in angiosperm families have shown a significant association between monoecy and dioecy, and researchers have proposed that dioecy has tended to evolve from monoecy. We evaluated this hypothesis in the context of a phylogeny of 918 monocotyledons assembled from 19 published trees. Binary and multistate breeding system characters were mapped onto a set of composi...

The evolution of breeding systems was studied in the genus Acer, with special attention to the origin of androdioecy and dioecy, using a phylogenetic approach. Parsimony and maximum-likelihood techniques were used to infer the ancestral character state and trends in the evolution of breeding systems. Information on breeding systems was obtained from the literature, and phylogenetic relationship...

UNLABELLED PREMISE OF THE STUDY Dioecy occurs in only about 6% of angiosperms, yet it has evolved many times from hermaphroditism. Polygamy is an even more uncommon condition within angiosperms, in which both unisexual and bisexual flowers occur within a species. Polygamy, dioecy, and hermaphroditism all occur within a New World clade of Galium (Rubiaceae), in which dioecy is hypothesized to...

We report on a phylogenetic analysis of correlations between the occurrence of dioecy and several ecological and life-history attributes: tropical distribution, woody growth form, abiotic pollination, small inconspicuous flowers and inflorescences, many-flowered inflorescences and fleshy fruits. Various hypotheses have been proposed to explain why associations occur between dioecy and several o...

A careful comparative analysis suggests a simple explanation for a category of exceptions to the general correlation between separate sexes in plants -- dioecy -- and self-incompatibility. In some genera, polyploidy causes failure of self-incompatibility, and dioecy may then evolve.

Sexual systems, particularly dioecy, and the habit correlations were examined for 3052 native angiosperms in Taiwan and 689 species from its outlying Orchid Island, and compared among different vegetation types. The majority of angiosperms in Taiwan are hermaphrodites (74.4%, N = 2272), followed by monoecious taxa (11.2%, N = 341), and then dioecious taxa (7.9%, N = 240) and polygamous taxa (6....

Dioecy, the sexual system in which male and female organs are found in separate individuals, allows greater specialization for sex-specific functions and can be advantageous under various ecological and environmental conditions. However, dioecy is rare among flowering plants. Previous studies identified contradictory trends regarding the relative diversification rates of dioecious lineages vs t...

We present a model for the gradual evolution towards dioecy in cosexual plants with geitonogamous selfing. We show how geitonogamous selfing (i.e., transfer of pollen between flowers on the same plant) can facilitate the evolution of dioecy (i.e., separate male and female individuals) in cosexual plants (i.e., both sexual functions on the same plant). We study the effect of parameters such as i...

Context The proportion of dioecious species can vary considerably among climates and habitats. However, studies often involve isolated communities or large diverse areas fail to capture how proportions across landscapes. Aims To identify (1) life-history associations terrestrial plant in central southern Australia, (2) whether dioecy varies spatially (3) is correlated with and/or climate factor...