Bazzania polita sp. nov., a rare New Zealand species (Lepidoziaceae, Marchantiophyta) with an assessment of branching type as a character

Bazzania polita sp. nov. is described from New Zealand from two collections. It resembles B. exempta in having leafy branches that are predominantly ventral-intercalary, but the leaves are more broadly rectangular, and the dorsal leaf margin is more ampliate. The underleaves of B. polita are connate with the leaves on both sides versus free in B. exempta, and they are toothed as well as lobed versus lobed but untoothed in B. exempta. Neither leaves nor underleaves of B. polita are caducous (leaves are caducous in B. exempta). The hyaline portion of the underleaf surface and the leaf margins of B. polita are asperulate, versus smooth throughout in B. exempta. Seven New Zealand species that commonly have leafy ventral-intercalary branches were sampled for variation between populations. In five species the proportion of leafy ventral-intercalary branches varied a great deal, suggesting that branching type in these species is environmentally influenced. If a species with a high proportion of leafy ventral-intercalary branches is known from a single specimen, it cannot be concluded that this is a constant feature of the species.