VARIATION IN THE EUCALYPTUS-GLOBULUS COMPLEX REVISITED

Patterns of variation in the Eucalyptus globulus Labill. complex are r eassessed by combining capsule measurements from an earlier study with recent collections, mainly of subspecies globulus. Four groups of pop ulations are apparent and can be ascribed to the four subspecies maide nii, psuedoglobulus, bicostata and globulus. Intergrade populations be tween the latter three subspecies are widespread and mainly occur in t he Otway Ranges and west Gippsland. There is a continuum in capsule mo rphology between the three-fruited subspecies, pseudoglobulus and bico stata. Subspecies globulus intergrades with these three-fruited interm ediates. Three-fruited intergrade populations occurring north and sout h of the range of core pseudoglobulus can be differentiated and probab ly represent intergrades between pseudoglobulus and bicostata and betw een pseudoglobulus and globulus respectively. Reports of bicostata in the Furneaux Group and southern Victoria are thus probably erroneous a nd result from convergence in capsule morphology. The previously descr ibed taxon E. stjohnii (R. T. Bak.) R. T. Bak. is part of the continuu m between subspecies pseudoglobulus and bicostata, but closer to pseud oglobulus. Populations phenotypically intermediate between and signifi cantly different from globulus and the three-fruited intergrades are h ighly variable and occur in western Tasmania, on the northern end of F linders Island, in the Otway Ranges and in west Gippsland. An isolated population on Rodondo Island is highly variable and has closest affin ities to pseudoglobulus despite being within the geographical range of core globulus. The population from King Island is intermediate betwee n the Otway phenotype and core globulus. The climatic regimes of the s ubspecies are markedly different and most three-fruited and globulus i ntergrade populations have closer climatic affinities to pseudoglobulu s and globulus respectively. Hypotheses relating to the origin of the pattern of variation in E. globulus are discussed.