Abstract: AN examination of specimens of an alga at first assigned to Vaughaniella rupicola Boergs. has led to the conclusion that the genus Vaughaniella Boergs.1 represents the basal rhizomatous portion of the genus Padina Adans. In southern Queensland, these flattened rhizomes, often showing transition to fan-shaped thalli, are found at the base of plants of Padina commersonii Bory in both estuarine and exposed localities; but around the margins of shallow lower littoral pools, on exposed rock platforms, rhizome development may sometimes take place without any production of fan thalli.