Casuarina equisetifolia (Beach Sheoak, Australian Pine)

Casuarina equisetifolia (Beach Sheoak, Australian Pine) is a species of evergreen tree in the Casuarinaceae family. It is native to the coastal regions of Southeast Asia, Australia, and the Pacific Islands, but has been introduced to many other parts of the world as an ornamental tree and for its commercial value. 

The tree typically grows up to 35 meters (115 feet) in height, with a narrow crown and a straight trunk that can reach up to 1 meter (3.3 feet) in diameter. The bark is rough and scaly, with a reddish-brown color. 

The leaves are reduced to scale-like structures, arranged in whorls around the stems, and are green to gray-green in color. The tree is monoecious, with separate male and female flowers on the same tree. The male flowers are long and cylindrical, and the female flowers are small and globular. 

The fruit is a woody cone-like structure, called a syncarp, that is made up of many small, winged seeds. These cones are persistent on the tree and can often be seen hanging from the branches. 

Casuarina equisetifolia is well adapted to coastal environments, as it can tolerate salt spray, wind, and poor soil conditions. It is commonly used for erosion control, windbreaks, and as a shade tree in parks and gardens. The wood is also valued for its durability and is used for construction, furniture, and firewood.

Reproduction: Beach Sheoak trees are dioecious, meaning they have separate male and female trees. The male trees produce cylindrical, yellowish-brown inflorescences known as "cones" that contain the pollen. The female trees produce small, inconspicuous flowers that give rise to woody, cone-like structures. The cones persist on the tree and contain numerous small winged seeds that are dispersed by wind.

Ecological Importance: Beach Sheoak trees play a role in stabilizing coastal soils and dunes, helping to prevent erosion. They also provide habitat and food sources for various bird species. Additionally, their fallen needles contribute to organic matter accumulation and nutrient cycling in coastal ecosystems.