Notes on Vallisneria (Hydrocharitaceae) in Australia, with descriptions of two new species

Vallisneria (Hydrocharitaceae) in Australia, with descriptions of two new species. Telopea 7(2): 111–118. Five species of Vallisneria are recognised from Australia, namely the cauline-leafed species V. caulescens and V. triptera and the non-cauline or tufted species V. americana (var. americana), V. nana and V. annua. Two of these, Vallisneria triptera and Vallisneria annua, are described here as new species from northern Australia, and an earlier name, Vallisneria nana R. Br., reinstated for a common Australian species. V. gracilis Bailey is recognised as a taxonomic synonym of V. nana, although many of the specimens previously identified as V. gracilis are now included in V. annua. Notes on all species and a key are given. The problems of comparing taxa growing in different countries and of applying correct names are discussed.