Casuarina cunninghamiana: Is known as the River Oak and is a member of the Casuarinaceae family. A few years ago the Australian members of the family were split into two genera. One is known as Casuarina and the other Allocasuarina. The only visible botanical difference is the colour of the seeds. Horticulturally there is no difference.Plants
The River Oak, as the name implies, occurs along watercourses. It is found in eastern NSW and Queensland. River Red Gum (Eucalyptus camaldulensis) occupies this niche in western areas. In NSW, both species meet in the Warrumbungle National Park.
Casuarina cunninghamiana is a tall, graceful tree with fine pine-like foliage. The bark is deeply fissured. Small cones (see image) contain a large number of pale, winged seeds. Male and female flowers are carried on different trees. Male flowers are in spikes and are carried on the ends of branches. When their pollen ripens, male trees assume a brown appearance. People are often concerned about the foliage colour change and think that the trees are either dying or diseased. River Oaks are wind pollinated so individual male flowers are insignificant.
In NSW, River Oaks are classified as protected plants, not because they are rare but because their roots are instrumental in reducing stream bank erosion.
There is something magical about the sound of wind blowing through River Oak foliage. Forests of River Oaks attract a wide range of bird species.
Casuarina cunninghamiana could be cultivated as a specimen tree or as a component of windbreaks and shelterbelts. In cultivation, they will cope with dry situations. There is a continual rain of small branches from River Oaks. This foliage builds up around the tree and forms useful mulch.
Propagate from seed. Pick the cones, keep them in a warm place and the winged seeds will be released in a couple of days.