Abstract
Evidence is provided for the first demonstrated example of allopolyploidy in the New Zealand fern flora. Cytological, morphological, and molecular (AFLP‐DNA fingerprinting) analyses indicate that the fern previously known as Polystichum richardii constitutes an allopolyploid complex, in which four separate evolutionary lineages are present. These are here recognised as three taxonomic species, with one of these encompassing two subspecies. The two allo‐octoploid lineages are accommodated under the reinstated name P. neozelandicum, each as a separate subspecies: P. neozelandicum subsp. neozelandicum and the new combination P. neozelandicum subsp. zerophyllum. The new combination P. wawranum is made for one of the tetraploid lineages, while the name P. oculatum is reinstated for the other. Polystichum richardii is a later synonym of P. neozelandicum, and hence is not a legitimate name for any of the taxa recognised here.