Laurencia similis (Ceramiales, Rhodophyta), a new species from Queensland, Australia

Abstract

Laurencia similis sp. nov. is described from Queensland, Australia. It resembles L. papillosa in having a thallus with numerous ultimate branchlets. The two species are inseparable on the basis of habit. However, L. similis differs from L. papillosa in anatomical features, such as pericentral cell number in sterile plants (four vs. two), the position of the fertile pericentral cells in the stichidium (fourth vs. second and third), the absence of fertile additional pericentral cells, and the presence of secondary pit connections between epidermal cells. The new species shows characters intermediate between the subgenera Laurencia and Chondrophycae, in contrast to L. papillosa, which belongs to the subgenus Chondrophycae.