Caulerpa sedoides f. geminata (Codiales, Chlorophyta) from Papua New Guinea, and a reappraisal of the different forms of C. sedoides

Study of the type specimen of Caulerpa sedoides f. geminata shows that the original description and illustrations of this taxon are not correct and induce confusion. The type specimen is compared with recent collections from Papua New Guinea. A corrected and more complete description, as well as illustrations are given and a comparison is made with other Caulerpa species with opposite ramuli. Other forms of C. sedoides (f. crassicaulis, f. tasmanica, f. mixta) as well as the bio-geographical distribution of this species, are discussed.