Australia's vast north-west coast can justifiably be described as a frontier wilderness: sparsely populated, incredibly beautiful but often inhospitable, with a rich but largely undocumented biodiversity. For over a decade, Dr John Huisman, in collaboration with students and colleagues, has collected and studied the marine plants of the region, these activities uncovering numerous undescribed genera and species and resulting in a manyfold increase in the known flora. His accounts of the marine algae will be presented in two volumes of the Algae of Australia series; this part describing the green and brown algae, to be followed by a second describing the red algae. This volume is an authoritative floristic account of the marine green and brown algae of northwestern Australia and includes 68 genera and 171 species.