Taxonomic and nomenclatural notes on the genus Cystoseira C.Ag.

Abstract

Taxonomic and nomenclatural confusions encountered in a study of the British species of Cystoseira are discussed; a number of non-British species, problems of whose synonymy have become involved with those of the British species, are also included. Fucus concalenatus L. is shown to be a synonym of F. foeniculaceus L. The combination Cystosira nodicaulis (With.) M. Roberts replaces C. granulata (L.) Grev., as the name C. granulata is illegitimate and its type does not belong to this speoies. Fucus selaginoides L. is the earliest description of Cystoseira tamariscifolia (Huds.) Papenf., but the combination C. selaginoides cannot here be used since Naccari had earlier employed the name to described another species. The identity of the type specimen of Fucus barbatus L. and other descriptions of this species are considered. Cystoseira fimbriata (Desf.) Bory is the correct name for the species often referred to as C. abrotanifolia CAg. The species currently known as C. discors (L.) Ag. has no legitimate name. Cystoseira iisneoides (L.) M. Roberts is shown to be the correct name of the species known as C. concatenata Ag. Cystoseira selaginoides Nacc, C. sauvageauana Hamel and C. hoppii sensu Valiante are briefly discussed; the last has no legitimate name.