Morphology and infrageneric position of three British species of Laurencia (Ceramiales, Rhodophyta)

Abstract The morphology of three British species of the red algal genus Laurencia (Ceramiales, Rhodophyta) has been studied. Laurencia obtusa (Hudson) Lamouroux, the type species of the genus, fits well into the traditional circumscription of subgenus Laurencia. Laurencia hybrida (De Candolle) Lenormand ex Duby and L. pinnatifida (Hudson) Lamouroux show many similar characters, and both are intermediate between the western Pacific species (subgenera Laurencia and Chondrophycus) and the eastern Pacific species (Spectabilis group) of the genus.