Since the publication of the package "EUCLID Eucalypts of South-eastern Australia" (1997, revised edition 2000) we have continued work on the interactive key and associated fact sheets, extending the coverage to include those drier areas of South Australia not originally covered and that species-rich part of Western Australia south of 26°S latitude, i.e. south of a line from the Northern Territory/South Australia border to Shark Bay on the Indian Ocean coast. "EUCLID — Eucalypts of Southern Australia" includes 690 species and subspecies of Eucalyptus and Angophora. We have taken a conservative approach in our taxonomy and include the genus Corymbia (the bloodwoods and ghost gums) as a subgenus of Eucalyptus. Similarly we have retained the genus Angophora.

There have been many new species of eucalypts described in the past decade for the area treated in this edition of EUCLID. At times we believe that distinctions between certain published taxa do not warrant specific recognition, e.g. Eucalyptus silvestris, we regard simply as a depauperate form of E. microcarpa. In these cases the later published name is synonymised with an existing name. Such rejected names are in a Synonymy Table which will direct the user to an existing name.

In other instances, we believe that taxa have been published on credible but slender grounds. We believe that the distinctions in the size of organs, for example, reflect only a minor genetic shift, e.g. between E. pseudoglobulus and E. bicostata which differ mainly in the prominence of the pedicel. We prefer to maintain these two taxa, originally published as species, as subspecies of E. globulus. A similar case is that of the recently published E. semiglobosa which had been raised to species level. We prefer to maintain it as E. goniantha subsp. semiglobosa as originally published. In other instances, we believe that some published taxa are better treated as synonyms, e.g. E. sparsicoma (now included in E. phaenophylla) and E. signata (now included in E. racemosa).

Presentation of the package is similar to that previously used. The interactive key uses the software package Lucid version 2.2. The character list has been slightly updated by the inclusion of geographic characters relating to the areas newly covered, the addition of two new morphological characters related to bud and fruit fusion, and by the exclusion of all sapling characters.

The format of the species Fact Sheets has been modified only slightly to now include description of seedlings, as this early growth stage can be very helpful in difficult identifications. The "Notes" section of the Fact Sheets has also been rewritten for all species, including a short paragraph about the subgroup to which a species belongs and why. We have attempted, as in previous editions, to include images showing for each species habit, bark, leaf venation, buds, flowers, fruit, juveniles and/or seedlings and a distribution map. In addition, we now include images showing what the seeds look like for all species where seeds are known.