Tmesipteris alticola (Psilotaceae), a new fern species endemic to New Caledonia

Abstract

ABSTRACT Tmesipteris alticola is described here as a new fern species endemic to New Caledonia's Grande Terre. It is a fifth species of Tmesipteris for the territory, and the second endemic. The obovate leaves and conic synangia of T. alticola distinguish it morphologically from all other species of Tmesipteris. Phylogenetic analyses of chloroplast DNA sequences support its distinctiveness, and indicate it is most closely related to T. truncata and T. vieillardii among the sampled species. Tmesipteris alticola is known from only four mountainous locations, all with ultramafic substrates in Province Sud, at elevations of 1200 m–1500 m, where it grows terrestrially or as a low epiphyte, seemingly mostly on ridges or around summits within short-statured cloud forest. We propose a provisional IUCN conservation status of Near Threatened for T. alticola because of its limited known occurrences. Tmesipteris alticola adds to a slew of fern species that have been recently newly described, reinstated, or recorded in New Caledonia.