Cosmianthemum is a genus of flowering plants belonging to the Acanthaceae family. The original range is Thailand, West Malesia. Species: Cosmianthemum angustifolium Bremek. Cosmianthemum anomalum B.L. Burtt & R.M.Sm. Cosmianthemum brookeae Bremek. Cosmianthemum bullatum B.L. Burtt & R.M.Sm. Cosmianthemum dido B.L. Burtt & R.M.Sm.