A morphometric analysis of Eucalyptus urophylla and related taxa with descriptions of two new species

Abstract

Over 400 specimens from 26 locations, mainly in the Lesser Sunda Islands and some from New Guinea and northern Cape York, were examined. These were representative of an array of forms ordinarily assigned to Eucalyptus urophylla, E. pellita and an undescribed species as well as those considered by some to be hybrid between E. alba and E. urophylla. The latter has long been considered to show considerable polymorphism. Re-examination of the available material and records suggest that interspecific hybridisation is not significantly involved in this variability. Although this examination pointed to the existence of some differentiation at the level of species in this array, there was still a core of material which could not be separated readily into subgroups. Measurements were taken of selected floral and foliar morphological features which were then subject to statistical analysis to ascertain if subgroups were discernible on this basis. As a result, the separation of two species, Eucalyptus orophila sp. nov. and Eucalyptus wetarensis sp. nov. from Eucalyptus urophylla sensu lato in the Lesser Sunda Islands, is supported. The related populations called species A by Pinyopusarerk et al. (1993), from New Guinea and northern Cape York, were to a somewhat lesser extent separated on these criteria. These results were paralleled by evidence from seedling morphology and oil characteristics. Isozyme analysis gave a similar grouping for the material from Wetar, but did not indicate other separations from the core E. urophylla.