The Breeding Biology of Epacris impressa. Is This Species Heterostylous?

Abstract

The suggestion that Epacris impressa is heterostylous is discussed in relation to an examination of the morphological characteristics and the incompatibility system of the species. The conclusion is reached that, although the style length is variable, the species does not exhibit either the full morphological or incompatibility syndromes associated with heterostylic systems. An interpretation is given suggesting E. impressa may represent the early stages of the evolution of heterostyly. The results of self- and crosspollination experiments are presented which confirm the view that E. impressa is a species which is essentially self-infertile, but a significant minority of individuals within each population demonstrate self-fertility.