Vascular flora of Norfolk Island: Some additions and taxonomic notes

Abstract

A total of 75 taxa (including 1 hybrid) are reported as new to the flora of the Norfolk Island group, in the south‐west Pacific Ocean. Of these 1 is endemic (Achyranthes margaretarum), and 10 (2 pteridophytes, 8 anthophytes) taxa are considered indigenous and appear to represent either new natural long‐distance colonisations of Norfolk Island group from Australia and New Zealand or are new identifications of indigenous taxa either treated under other indigenous names or as naturalised in the Norfolk Flora. The remaining 64 taxa are considered naturalisations from resident gardens, or recent arrivals via human traffic from Australia or New Zealand. Aside from these records we discuss and update information on a further 27 taxa either covered by the last Norfolk Island flora treatment, or noted in subsequent works. A new species, Geranium gardneri, is described and treated as indigenous to Australia and naturalised in Norfolk I. and New Zealand. Nephrolepis flexuosa is reinstated for the non‐tuberous, high‐polyploid fern previously included within a broad circumscription of N. cordifolia, and which is indigenous at least to Norfolk I., Raoul I., Lord Howe I., New Zealand, and Fiji. The new combination Boehmeria australis subsp. dealbata is made for the Raoul I. (Kermadec Islands group) endemic, and Elymus multiflorus subsp. kingianus for the Norfolk and Lord Howe Island wheatgrass. The New Zealand Cordyline kaspar and Raoul I. Rhopalostylis cheesemanii are relegated to synonymy within the Norfolk I. Cordyline obtecta and Rhopalostylis baueri, respectively, which are now no longer considered endemic. Dianella intermedia and Pennantia endlicheri are treated as endemic to Norfolk I. and Senecio australis as indigenous. Two species, Ipomoea cairica and Oxalis exilis, previously treated as naturalised are recognised as indigenous, while Homalanthus populifolius is now considered naturalised and so is excluded from the indigenous flora. Anew treatment for Norfolk I. Oxalis Sect. Corniculatae is offered, and three of the four taxa reported from the island group but treated by the current flora as part of O. corniculata sens. lat. are recognised at species rank. Of these we consider only one, O. exilis, to be indigenous, and treat O. choonodes and O. radicosa as probably naturalised. We also report the first naturalised occurrence of O. corniculata sens. str. from the island group and exclude O. perennans from the flora. Isolepis cernua var. setiformis is recognised for the Norfolk I. Isolepis previously treated as probably endemic and unnamed.