Frullania wairua, a new and seemingly rare liverwort species from Northland, New Zealand

The liverwort Frullania wairua sp. nov. (Jubulaceae) from Northland, New Zealand, is described and illustrated. The combined characteristics of the leaf, stem-underleaves, cell-wall anatomy, and oil-bodies distinguish it from all other New Zealand species of Frullania. A critical comparison is also made between Frullania wairua and morphologically allied subtropical species of botanical regions elsewhere. This new species is remarkably interesting in comparison with almost all other Frullania species in New Zealand because of its apparent rarity. The conservation status of Frullania wairua in the New Zealand threat category is determined as Nationally Critical. Minor elements of the New Zealand threat classification system that are difficult to apply to bryophytes are noted.