A brief description is given of the Eucalyptus genus showing the wide variations of morphological characters. The different classifications that have been proposed are outlined. A review of chemotaxonomic studies indicates that the polyphenols in eucalypt leaves could be the most useful compounds for taxonomic purposes. Over 80 per cent of the known species of eucalypts have been examined chromatographically for these compounds. The methods of examination are described and the chromatographic data of the primary polyphenols recorded. The composition of the polyphenols in the leaves of the species in the series Globulares is presented when it is clearly seen that E. preissiana, E. megacarpa and E. coronata have been wrongly placed.