Allocasuarina verticillata, commonly known as drooping she-oak or drooping sheoak, is a nitrogen fixing native tree of southeastern Australia. Originally collected in Tasmania and described as Casuarina verticillata by French naturalist Jean-Baptiste Lamarck in 1786, it was moved to its current genus in 1982 by Australian botanist Lawrie Johnson. It grows as a small tree with a rounded habit, reaching 4–10 metres (12–35 ft) in height. The species occurs in Australian Capital Territory, New South Wales, South Australia, Tasmania, and Victoria.