Seven species of Porella are present in Australasia and the south Pacific: P. acutifolia (Lehm. & Lindenb.) Trevis. var. acutifolia, P. acutifolia var. linguifolia (Steph.) M. L. So, comb. nov., P. cranfordii Steph., P. elegantula (Mont.) E. A. Hodgs., P. geheebii (Steph.) Grolle, P. grollei S. Hatt., P. maxima (Steph.) M. L. So, comb. nov., and P. viridissima (Mitt.) Grolle. Porella pulcherrima Herzog & S. Hatt. is placed under the synonymy of P. elegantula, and P. queenslandica (Steph.) S. Hatt. under P. cranfordii. Porella hirtella (Steph.) S. Hatt. and P. novoguinensis S. Hatt. are treated as synonymous with P. maxima. Porella javanica (Steph.) S. Hatt. is excluded from the region. Lectotypes are designated for Madotheca latifolia Colenso and M. amoena (Colenso) Martin. A key to all the species in the region is provided.
Communicating Editor: Alan Whittemore