Application of morphometric techniques to the taxonomy of the genus Grammitis Sw. (Filices: Grammitidaceae) in SE Australia and New Zealand

Grammitis Sw. is a genus of small ferns found mostly in tropical regions in mossy, high altitude forests. It occurs in south eastern Australia and New Zealand, where it has been poorly understood until recently. The taxonomy of the genus has been less than satisfactory, with all material being lumped by most workers into a single variable species, G. billardieri Willd. In 1975, Parris, and in 1976, Parris and Given published revisions of Grammitis for Australia and New Zealand, respectively, establishing the new species, G. meridionalis, G. stenophylla, G. rawlingsii, G. pseudociliata and G. givenii as well as a number of tropical ones. However, these revisions do not always distinguish satisfactorily between these new species and those previously described. In an attempt to clarify the status of the species in Australia and New Zealand, multivariate statistical techniques were applied to a wide range of characters (including biochemical ones). Another research objective was to assess the suitability of various statistical techniques for making taxonomic decisions such as those required in this study. The techniques used included both univariate and multivariate analysis of variance, quadratic discriminant analysis, stepwise linear discriminant analysis, single linkage cluster analysis using K-dissimilarities based on normal information radii and Akaike's information criterion. With the exception of cluster analysis, these techniques gave better species definition than classical techniques as presently applied. It was determined that G. meridionalis Parris is distinct from G. billardieri Willd., but that it is difficult to separate from G. magellanicaDesv., and may need to be reduced to a subspecies of the latter. It was further determined that certain populations of Grammitis in Tasmania are identical with G. magellanica Desv. ssp. magellanica, and G. patagonica (C. Chr.) Parris, respectively, both of which are presently recognized as being restricted to South America and the territory of New Zealand. The subspecific compositions of G. poeppigiana (Mett.) Pic. Ser. and of G. magellanica Desv. were examined, and no evidence was found for any change to the status quo, other than the possible incorporation of G. meridionalis Parris into G. magellanica Desv. Finally, the application of these statistical techniques suggested that certain populations from Western Tasmania may represent an undescribed species. Further work, outlined in this thesis, needs to be undertaken to determine the status of both of these last populations.