typica Domin Casuarina equisetifolia, commonly known as coastal she-oak, horsetail she-oak,[3] ironwood,[4] beach sheoak, beach casuarina, whistling tree[5] or Australian pine[6] is a species of flowering plant in the family Casuarinaceae and is native to Australia, New Guinea, Southeast Asia and India.

incana in Flora Australiensis,[10] and in 1982, Lawrie Johnson changed the names to subspecies equisetifolia and incana respectively, in the Journal of the Adelaide Botanic Gardens:[11] There is some doubt as to whether Linnaeus' publication of C. equisetifolia is valid, since he based his description solely on Rumphius's description of Casuarina litorea in Herbarium Amboinense[17] and there are no type specimens.

equisetifolia grows near the sea, behind beaches and near estuaries, sometimes on rocky headlands in Australia, New Guinea, Southeast Asia and India.

[2] It is an invasive species in the United States, but biological control by insects, including by a Selitrichodes wasp and Carposinidae and Gelechiidae moths, has been effective.

[23] Casuarina equisetifolia is an actinorhizal plant able to fix atmospheric nitrogen[24] through a symbiotic relationship with strains of Frankia, a actinomycete hosted in nodules on its roots.

The leaves were found to be useful as absorbent material for the removal of textile dyes, such as reactive orange 16,[26] Rhodamine B,[27] methylene blue, malachite green[28] and methyl violet 2b.

[36] In the island of Langkawi, Kedah, Malaysia, there is a sand spit in the mouth of the Ayer Hangat river in the Kilim Karst Geoforest Park about 20 km from the town of Kuah also named Tanjung Rhu, where a line of these trees may be seen.

[39] Casuarina equisetifolia exhibits a high degree of adaptability to different environmental conditions, including coastal habitats, sandy soils, and disturbed areas.

The species is frequently planted for erosion control, windbreaks, and ornamental purposes, inadvertently introducing it to new areas where it can become invasive.