Towards a better understanding of the Ruppia maritima complex (Ruppiaceae): Notes on the correct application and typification of the names R-cirrhosa and R-spiralis

Ruppia cirrhosa and R. maritima are two widely used names, each applied respectively to a long-and coiled-pedunculate species or a short-and non-coiled pedunculate species of Ruppia. The nomenclatural history of the two names is outlined here. A lectotype for the name R. cirrhosa is designated and the name is shown to be a homotypic synonym of R. maritima. Consequently, R. spiralis has nomenclatural priority over R. cirrhosa for the long-and coiled-pedunculate Ruppia.