A revision of the Thelymitra pauciflora R.Br. (Orchidaceae) complex in Australia

Abstract

The Thelymitra pauciflora R.Br. complex is defined as a group and the Australian members are revised. Fifteen new species, Thelymitra albiflora Jeanes, Thelymitra basaltica Jeanes, Thelymitra batesii Jeanes, Thelymitra bracteata J.Z.Weber ex Jeanes, Thelymitra brevifolia Jeanes, Thelymitra cyanapicata Jeanes, Thelymitra exigua Jeanes, Thelymitra frenchii Jeanes, Thelymitra inflata Jeanes, Thelymitra lucida Jeanes, Thelymitra pallidiflora Jeanes, Thelymitra peniculata Jeanes, Thelymitra viridis Jeanes, Thelymitra vulgaris Jeanes and Thelymitra xanthotricha Jeanes, are described and illustrated. The key diagnostic features relating to the morphology of the post-anther lobe of the column (its size, shape, degree of inflation and degree of apical notching), the lateral lobes (their length, thickness and curvature), the trichomes on the lateral lobes of the column (their distribution, length, number, coarseness and colour), the leaf (its length, width, texture and shape) and the sterile bracts (their number and degree of divergence from the scape) are discussed where relevant. Information on distribution, habitat, flowering time, pollination biology and conservation status is given for all taxa. The relationships between T. pauciflora and the other taxa in the complex are discussed. Detailed notes are given on the typification and characterisation of the poorly known species Thelymitra angustifolia R.Br., Thelymitra arenaria Lindl., Thelymitra holmesii Nicholls, Thelymitra mucida Fitzg. and T. pauciflora. A dichotomous key is provided.