The first edition of this work appeared in a single volume in 1969. Now, about a quarter of a century later, so many additional species had to be included, that two volumes are needed. Most of the additions are new species described since 1969, partly as a result of the splitting tendencies of some recent Australian botanists, of which Dockrill is highly critical. Each species is described in detail and illustrated with a full-page line drawing. While perhaps not of professional quality, the drawings are sufficiently clear and accurate to make the task of identifying almost any tropical Australian orchid a light one. In addition, all genera and species are keyed out. The distribution within Australia is usually given in considerable detail, but for those without an encyclopedic knowledge of Australian topography it is often difficult to get an idea of the area concerned. A few maps, and some degree of standardization would have been helpful.