The southern Australian species of Laurencia (Ceramiales: Rhodophyta)

Species of Laurencia along southern Australian coasts are common and often ecologically important. Sixteen species are recognized from this region, of which L. aldingensis, L. shepherdii, L. brandenii and L. tumida are newly described. While most species are clearly defined, L. filiformis as recognized includes three main forms (one of which is based on L. heteroclada), with intergrades between them, and also some intergrades from it to the related species L. arbuscula and L. tasmanica. Most southern Australian species appear to be confined to this region and their biogeography is discussed; the widely distributed L. obtusa probably does not occur in southern Australia.