A small world: Uncovering hidden diversity in Frullania – a new species from Aotearoa-New Zealand

Frullania is a large and taxonomically complex genus. Here a new Frullania, F. toropuku von Konrat, de Lange & Larrain, sp. nov. is described from New Zealand. Frullania toropuku is placed in F. subg. Microfrullania. The new species is readily recognised by a combination of morphological characters associated with branching, the perianth, sexuality, and sporophyte, which distinguish it from all other New Zealand and regional species of Frullania. However, morphologically F. toropuku most closely resembles the widespread F. rostrata, which might well be regarded as a Southern Hemisphere equivalent of the Holarctic F. tamarisci species-complex in terms of its cryptic diversity. A combination of morphological characters associated with branching, the perianth, sexuality, and sporophyte distinguish F. toropuku from all other New Zealand and regional species of Frullania. A comparison is made between F. toropuku and morphologically allied species of botanical regions outside the New Zealand region and an artificial key is provided. In a prior investigation, maximum parsimony and maximum likelihood analyses of nuclear ribosomal ITS2 and plastidic trnL-trnF sequences from purported related species confirms its independent taxonomic status and corroborates its placement within F. subg. Microfrullania. The ongoing studies of Frullania species-complexes reveal the urgent need for more species-level phylogenies with extensive population sampling to approximate the actual diversity of Frullania, and to elucidate speciation processes and distribution range formation.