Davallia (Pteridophyta) in New Zealand, including description of a new subspecies of D-tasmanii

The fern genus Davallia is represented by two taxa in New Zealand; both are restricted in their distribution. D. tasmanii subsp. tasmanii is limited to the Three Kings Islands, north-west of Cape Reinga, New Zealand. The second taxon was discovered in 1984 and is known only from a single population in Puketi Forest, Northland. It is described as a new subspecies, D. tasmanii subsp. cristata. It differs from D. tasmanii subsp. tasmanii in the presence of multiseptate hairs that are restricted to the apex of the rhizome scale, conspicuous false veins, less complex venation pattern, and the generally smaller frond features. Both extant New Zealand taxa may have diverged ti om a common ancestor, but a previous suggestion that D. tasmanii subsp. tasmanii is derived from D. canariensis is rejected. The conservation status of both taxa are assessed, with an outline of potential threats to their habitat.