Spongites fruticulosus (Corallinaceae, Rhodophyta), the type species of Spongites, in southern Australia

Abstract

Spongites fruticulosus Kützing, the type species of Spongites (Corallinaceae, Rhodophyta), which was previously known for certain only from the type specimen, occurs commonly along the southern Australian coast. The vegetative thallus exhibits considerable variation, and cells in the ventral region can either be arranged in a more or less coaxial or in a non-coaxial manner. Gametangia and carposporophytes are described for the first time. Spermatangia are simple and restricted to the floor of the male conceptacle chambers. Gonimoblast filaments arise only from the margins of fusion cells that appear to be continuous and cover most of the conceptacle chamber floor. On the basis of these data, Spongites fruticulosus is now more completely characterized as a species, and it is possible to consider the relationships of Spongites to other genera of the subfamily Mastophoroideae. Historical information on S. fruticulosus and relevant nomenclatural data are also included.