P. australis

P. australis may refer to:
 * Pachyornis australis, the crested moa, an extinct bird species
 * Paracalliope australis, an amphipod crustacean species in the genus Paracalliope found in Australasia
 * Petaurus australis, a marsupial native to eastern Australia
 * Phaius australis, an orchid species
 * Phasianella australis, the Australian pheasant, painted lady and pheasant snail, a medium-sized to large species of sea snail species found in Australia
 * Phragmites australis, the common reed, a large perennial grass species found in wetlands throughout temperate and tropical regions of the world
 * Planchonella australis (syn. Pouteria australis), the black apple, a tree species native to Australia
 * Polylepis australis, the tabaquillo or queñoa, a tree species endemic of central Argentina
 * Posidonia australis, the fibreball weed, a seagrass species found in the southern waters of Australia
 * Pseudechis australis, the common king brown or Mulga snake, a highly dangerous snake species found in Australia
 * Pseudomys australis, the plains rat, a threatened rodent species native to Australia
 * Pseudophryne australis, the red-crowned toadlet, a ground frog species restricted to the Sydney Basin, New South Wales, Australia