Pollen morphology of Andrographideae (Acanthaceae)
Pollen morphology of Andrographis Wallich, Cystacanthus T. Anderson, Diotacanthus Bentham, Gymnostachyum Nees, Haplanthus Nees and Phlogacanthus Nees from Andrographideae (Acanthaceae) is described and illustrated. Pollen morphological variation is compared to accepted generic limits. Pollen morphology provides additional discrete character support for Andrographis, Diotacanthus, Haplanthus and Phlogacanthus being monophyletic but not for Cystacanthus and Gymnostachyum. Previous attempts to diagnose Andrographideae pollen are discussed and a new diagnosis is given. A dichotomous key for the identification of genera by pollen morphology is provided. Rhombochlamys and Hulemacanthus, which have been classified with Andrographideae on the basis of pollen morphology, are discussed and illustrated. © 1992.