Resolution of the Thelymitra canaliculata R.Br. (Orchidaceae) complex in Southern Australia

Abstract

The five currently known taxa in the Thelymitra canaliculata R.Br. complex from southern Australia are discussed and description are presented for each. Thelymitra jonesii Jeanes from Tasmania, Thelymitra latiloba Jeanes from southwestern Australia and Thelymitra occidentalis Jeanes from southern Australia are described as new and illustrated. The key diagnostic features relating to the size, shape and relative position of the auxiliary lobes of the column and the size and shape of the post-anther lobe of the column are elucidated. Information on distribution, habitat, polination biology and conservation status is given for all five taxa. The relationships between Thelymitra canaliculata, Thelymitra azurea R.S. Rogers and the three new species are discussed. A key is provided to distinguish all five members of the Thelymitra canaliculata complex.