Towards resolution of the Prostanthera ovalifolia R.Br. assemblage (Lamiaceae: Prostantheroideae): clarification of P. cineolifera R.T.Baker & H.G.Sm. and description of three new species

The circumscription and application of Prostanthera ovalifolia R.Br. appears to have been based largely on leaf shape, leading to a geographically and morphologically diverse concept of the species. This approach has completely or partially subsumed other species (namely P. atriplicifolia A.Cunn. ex Benth., P. latifolia (Benth.) Domin, P. lanceolata Domin and P. cineolifera R.T.Baker & H.G.Sm.), and included considerable variation hypothesised by some authors as distinct species (viz. P. sp. Hawkesbury (B.J. Conn 2591), P. sp. Olney State Forest (R.L. Palsson 166) and P. sp. Oxley Wild Rivers National Park (J.B. Williams s.n. NE 91044)). Morphological and molecular data, supported by phytochemical data, are used to partially resolve the taxonomy of this group. The circumscription of Prostanthera cineolifera is clarified and the name lectotypified. Three new species from New South Wales are recognised: Prostanthera dyarubbin Palsson & R.T.Mill., P. faucicola Palsson & I.Telford and P. milleri Palsson & J.J.Bruhl. Prostanthera milleri fits the criteria of Critically Endangered. We also lectotypify Prostanthera ovalifolia.