A morphometric analysis of eucalyptus urophylla and related taxawith 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 ordinarilyassigned to Eucalyptus urophylla, E. pellita and an undescribed species as well as those considered bysome to be hybrid between E. alba and E. urophylla. The latter has long been considered to showconsiderable polymorphism. Re-examination of the available material and records suggest thatinterspecific hybridisation is not significantly involved in this variability. Although this examinationpointed to the existence of some differentiation at the level of species in this array, there was still a coreof material which could not be separated readily into subgroups. Measurements were taken of selectedfloral and foliar morphological features which were then subject to statistical analysis to ascertain ifsubgroups were discernible on this basis. As a result, the separation of two species, Eucalyptus orophilasp. 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), fromNew 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. Isozymeanalysis gave a similar grouping for the material from Wetar, but did not indicate other separations fromthe core E. urophylla.