Chromosome numbers of Gracilaria foliifera and Gracilaria sp. (Rhodophyta) and attempted hybridizations

Abstract
Two species of Gracilaria, G. foliifera (Forsk.) Børg. and G. verrucosa (Huds.) Papenf., have been recorded from the Maritime provinces of Canada (South & Cardinal, 1970), although in recent years only G. foliifera var. foliifera is listed (South, 1976). These species are also known from the British Isles (Parke & Dixon, 1976). Chromosome counts of G. foliifera (Greig-Smith, 1954: as G. multipartita) and of G. verrucosa (Magne, 1964) from the European flora suggest these are distinct species.