The genus Acromastigum in Australia

Abstract

Eleven species of Acromastigum are recognised for Australia. Two species and one subspecies from Tasmania, A. prismaticale sp. nov., A. interstisiale sp. nov. and A. furcatifolium subsp. fumosum ssp. nov. are new. A. interstisiale also occurs in New Zealand on the Denniston Plateau. Two species, A. tenax and A. divaricatum, are new records for Australia, both are known from few collections, those of A. tenax from the Wet Tropics Bioregion and A. divaricatum from Tasmania. A. divaricatum is also reported for the New Zealand Botanical Region. The enigmatic New Zealand endemic A. brachyphyllum is synonymised with A. anisostomum, which is excluded from the Australian flora as Australian records are all based on misidentifications, primarily of A. interstisiale but also of A. mooreanum and A. furcatifolium subsp. fumosum. Both subspecies of A. furcatifolium are apparently sparsely distributed, subsp. furcatifolium on sandstone in rainforest in the Blue Mountains west of Sydney and subsp. fumosum on peat in rainforest and shrublands in Tasmania. A. exiguum and A. marginatum are retained as separate species distributed either side of the Tasman. A key, descriptions, illustrations and associated observations for Australian species are presented.