Transfer of the New Zealand red alga Tylotus proliferus (Gracilariaceae, Gigartinales) to the genus Gracilaria

Abstract

Reproductive material of Tylotus proliferus (Harvey) Kylin from the North Island of New Zealand has been examined and found to conform to the genus Gracilaria. Because the name Gracilaria prolifera Reinsch is in current use for an alga from South Georgia in the subantarctic, the new name G. truncata is proposed, based on a prominent branch feature of the New Zealand species. Details of habit, vegetative morphology, and carposporophyte development of G. truncata are presented. The so-called “nutritive filaments” which characterise this and many other species of Gracilaria arc discussed, and substitution of the term “traversing filaments” is suggested to avoid implying an unverified nourishment function of these structures. Some speculations on the possible relatives of G. truncata are made.