Any of the chiefly Australian trees that make up the genus Casuarina (family Casuarinaceae), which have whorls of scalelike leaves and segmented stems resembling horsetails .
Several species, especially C. equisetifolia , are valued for their hard, dense, yellowish to reddish brown wood, which is strong and reputed to be resistant to termite attack. Beefwood and ironwood are common names that reflect the wood's colour and hardness.