Blue Flower Pigmentation and Evolutionary Advancement

Abstract

It is often stated that characters which are subject to strong selective pressure are unsuitable for taxonomic purposes. Among such characters, the one which comes to mind most readily in angiosperms is flower colouration, where “there is clear evidence of natural selection for particular colours in different environments, according to the most active pollinators which are present” (Harborne 1977b). If, however, environmental pressures were indeed the only, or even the dominating factors, a trend towards the representation in all families of all colourations should be noticeable. This is not the case (Gottsberger and Gottlieb 1980, 1981).