Floral correlations in an andromonoecious species, Commelina communis (Commelinaceae)

The sizes of various floral organs of andromonoecious Commelina communis were measured to test the hypothesis that size correlations among floral organs are regulated by natural selection. Size correlations among six floral organs in both perfect flowers and staminate flowers with sterile pistils were compared. The stigma-long stamen anther (L-anther) correlation for perfect flowers was the strongest of all C. communis floral correlations, whereas this correlation was weak in staminate flowers. This suggests that the position of fertile stigmas may have evolved to maximize receipt from pollinators of pollen grains from L-anthers of the same height in perfect flowers.