Discovering Australia's evolutionary past
Box 2 | The name game – Australia's eucalypts and acacias
With the help of comparative DNA analyses and other analytical techniques, more and more information has become available about the relationships between different groups of plants. In some cases, the information has revealed previously unanticipated relationships. As a result, scientists are reclassifying and regrouping some members of the plant kingdom.
In 1979, Australian botanists Barbara Briggs and Lawrie Johnson proposed that the Eucalyptus genus be divided into eight genera, based mainly on distinctive floral and bud structures, but this re-classification was never formally implemented. In 1995 Lawrie Johnson and Ken Hill did split the Eucalyptus genus up, but only into two genera, Eucalyptus and Corymbia, on the grounds that Corymbia (the bloodwoods) were more closely related to members of the Angophora genus than to other eucalypts. This proposal was also supported by data collected from DNA analyses of the eucalypts done in 1995, the first for any major group in the Australian flora.
Most botanists and native plant enthusiasts accept the Johnson-Hill scheme of three genera-Angophora, Corymbia and Eucalyptus.
For example, some of Australia's most familiar gum trees like the scarlet flowering gum became Corymbia ficifolia, while the lemon-scented gum became Corymbia citriodora.
The gum trees are however not the only group of Australian plants subject to a name change.
Comparative DNA and morphological analyses by Australian researchers supported the view that Australian acacias – the generic name for Australia's wattles – formed a distinct group of plants to the acacias found in other parts of the world, justifying their assignment to a new genus. But the daunting task of renaming all the species within the Acacia genus delayed such action.
In 2005, delegates at the International Botanical Congress in Vienna voted to retain Acacia as the generic name for the wattles of Australia. In doing so, delegates avoided the task of renaming some 950 species of the Acacia genus.
Related sites
Eucalypts but not Eucalyptus
(Australian plants online, Australia)
Corymbia, Corymbia...wherefore art thou Corymbia?
(Australian plants online, Australia)
The name Acacia retained for Australian species (Centre for Plant Biodiversity Research, Australia)
Posted October 2007.