C. equisetifolia Bark and leaf-alike branchlets.Female cones of C. equisetifoliaC. equisetifolia: habitus in Brazil
Casuarina, also known as she-oak, Australian pine and native pine, is a genus of flowering plants in the family Casuarinaceae, and is native to Australia, the Indian subcontinent, Southeast Asia, islands of the western Pacific Ocean, and eastern Africa.
Plants in the genus Casuarina are monoecious or dioecious trees with green, pendulous, photosynthetic branchlets, the leaves reduced to small scales arranged in whorls around the branchlets, the male and female flowers arranged in separate spikes, the fruit a cone containing grey or yellowish-brown winged seeds.
Description
Plants in the genus Casuarina are dioecious trees (apart from C. equisetifolia that is monoecious), with fissured or scaly greyish-brown to black bark. They have soft, pendulous, green, photosynthetic branchlets, the leaves reduced to scale-like leaves arranged in whorls of 5 to 20 around the branchlets. The branchlets are segmented at each whorl with deep furrows that conceal the stomates. Male flowers are arranged along branchlets in spikes with persistent bracteoles, female flowers in spikes on short side-branches (effectively "peduncles") that differ in appearance from vegetative branchlets. After fertilisation, the female spikes develop into "cones" with thin, woody bracteoles that extend well beyond the cone body. The cones enclose grey or yellowish-brown winged seed known as samaras.
Ecology
Casuarina are attacked by a range of herbivorous insects.
Curculionidae: A weevil in genus Haplonyx feeds on cones. The genera Misophrice and Apion have also been recorded on Casuarina, but the nature of their associations is unknown.
The genus Casuarina was first formally described in 1759 by Carl Linnaeus in Amoenitates Academicae and the first species he described (the type species) was Casuarina equisetifolia. The generic name is derived from the Malay word for the cassowary, kasuari, alluding to the similarities between the bird's feathers and the plant's foliage.
↑Wilson, Karen L.; Johnson, Lawrence A.S. George, Alex S. (ed.). "Casuarina". Australian Biological Resources Study, Department of Climate Change, the Environment and Water: Canberra. Retrieved 22 April 2023.