Batrachospermum (Batrachospermales, Rhodophyta) in Australia and New Zealand: New taxa and records in sections Contorta and Hybrida

Six species of Batrachospermum from Australia and New Zealand have a twiste d to coiled carpogonial branch and determinate gonimoblast filaments, and a re therefore referable to section Contorta or Hybrida. Batrachospermum aust ralicum Kutz. ex sp. nov. from large rivers in tropical Northern Territory has a tightly 3-coiled carpogonial branch; B. vittatum sp. nov. from tropic al Northern Territory has a characteristic longitudinal mid-whorl band of s permatangia; and B. deminutum sp. nov. from a single locality in eastern-ce ntral New South Wales has reduced whorls and long carpogonial branches. The other three species are cosmopolitan in distribution: B. virgatodecaisnean um Sirodot is widespread but uncommon in temperate regions of both countrie s; B. ambiguum Montagne is widespread and common in tropical Australia; and B. globosporum Israelson is restricted in Australia to near Brisbane in su btropical southern Queensland.