It is in the nature of biological research that discoveries are continually being made. Since EUCLID was first launched in October 1997, new species have been discovered. In this revised edition we have included three recently described species of the traditional genus Eucalyptus that did not appear in the first version. We have removed one species, E. interstans, because we now believe it is confined to Queensland. In addition, and of considerable interest to the eucalypt amateur and scholar alike, we have added the genus Angophora. This group of twelve taxa has long been regarded as close to Eucalyptus. It has been stated by many authors that it should be in the same genus. One such writer said that Angophora was indistinguishable from some eucalypts "except for the coherence of the petals to form an operculum". In fact, some species of the bloodwood eucalypts have distinct petals that lie flat in the form of an operculum and do not "open" as in Angophora, indicating the close relationship between the two groups. In common parlance, therefore, we suggest that all species in EUCLID should be referred to as "eucalypts" while implying that the words "Eucalyptus" and "eucalypt" refer to both groups as a whole.

In presentation, the new edition is enhanced by the addition or upgrading of nearly 200 new taxon images, and the addition of four new fully illustrated characters.