Correlation patterns among floral traits in Cleome viscosa L., a sexually polymorphic species

摘要

Cleome viscosa L., a multipurpose species, is reproductively versatile exhibiting variation in the sex of its flowers. Being predominantly andromonoecious, few plants occasionally exhibit functional monoecy. Andromonoecy is distinguished by the production of hermaphrodite and staminate flowers, while formation of pistillate, male and other intermediate flower types leads to functional monoecy. Size variation in these sexes is equally prevalent. Size dimorphy in all the flower types leads to significant differences in almost all the morphological features. Overall 12 different flower types thus distinguished were analysed for different morphological traits. The data generated were subjected to correlation analyses to determine the extent of relationship between them, and thereupon reflect on the mechanism of their selection in flowers of different sexes and sizes. Despite male fitness traits being at greater advantage in all flower types, female fitness is equally selected in hermaphrodites and exclusively in pistillate flowers. Others with staminodes show mixed fitness. A critical analysis of the morphological data and their correlations suggests that different pairs of traits in each flower type are evolved in ways unique to them and to maximize their functional potential. Natural selection is thus operating through differential correlation patterning and is probably driving the evolution of these flower types.