Taxonomic notes on the New Zealand flora: recognition of two subspecies in Dicksonia lanata

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Dicksonia lanata subsp. lanata and D. lanata subsp. hispida are raised from varietal rank and recognised here as separate subspecies. The former is distinguished primarily by the lack of a trunk and the presence of dense clusters of woolly, chestnut brown hairs at costa junctions on the underside of the laminae; the latter has short arborescent trunks, and longer, rigid, red–brown hairs among shorter, fine, pale brown hairs on the underside of the costae and pinna midribs. Previous genetic analyses of both subspecies support this distinction. The rank of subspecies rather than species has been chosen because the two groups are allopatric and, as far as is known, not reciprocally monophyletic. Subspecies hispida occurs from North Cape to the northern Kaipara Harbour and Great Barrier Island, and subsp. lanata from Thames to the Ruahine Ranges and on the north and west coasts of the South Island. Plants from the southern Coromandel Peninsula are of somewhat equivocal status but are treated here as belonging to subsp. lanata; they are similar to subsp. lanata in lacking a trunk, but have hair characters that in most cases do not clearly correspond to those of either subspecies. This article is a contribution towards clarifying the taxonomic and nomenclatural status of New Zealand plants for the plant names database (Ngā Tipu Aotearoa) and the electronic Flora of New Zealand.