Coastal She-oak

~ Casuarina equisetifolia ~

Billai in the Turrbal language

CASUARINACEAE

The swaying casuarinas are a familiar feature of our beachy landscapes in the east, with their soft, sonorous needle-like foliage sighing with a coastal breeze. They have a large and protective canopy that will shield you from strong winds and the harsh sun, and are an important stabilisation for those precious sand dunes. Also named the Whistling Tree and Beach Pine, the tree is a botanical wet-dream with its many unique functions and features. It’s wind pollinated and produces a male flower as well as a female flower (aka monoecious). It also has a symbiotic relationship with a nitrogen-fixing actinobacteria of the genus Frankia. Contact with this bacteria results in nitrogen-fixing nodes forming on the roots, which increases the nitrogen in the surrounding soil.

WHERE TO LOOK

The Coastal She-oak can be found sunbathing along northern New South Wales and Queensland beaches from Coffs Harbour up to the Gulf. It’s widespread and a prominent resident of most Sunshine Coast beaches. It can also be seen on some Coral Sea islands off the mainland and in cultivation through Sydney, Melbourne and Canberra.

FEATURES

The Coastal She-oak is a 6–35m evergreen tree. The stunning feature of this plant is its modified branches masquerading as incredibly delicate and drooping, needle-like leaves 5–8cm long and 4mm wide. The actual leaves sit tiny and scale-like along these branches or stems. Its male flowers present on the end of the needle-like branchlets and the larger red female flowers sit to the side of some branches. These female flowers, when pollinated, form into hard, woody, spiky fruit measuring 2–3cm (they look a bit like a conifer cone).

FLOWERING SEASON

Autumn and winter → Flowers can be seen through the cooler months.

TRADITIONAL USES

Children would be placed on the fallen leaves under the tree’s protective canopy as snakes avoid this area. It has been used as a source of wood to make boomerangs and the cones can be harvested for the salt content and chewed on to relieve thirst.

PLANTING

Casuarinas are fast growing and hardy as! They’ll endure sand, salt, wind, sun, shade, drought and nutritionally poor soil – this hardiness can also make them a bit of a pest outside of their natural environment. Plants and seeds are widely available online and in nurseries, with germination occurring between 14 and 28 days. Plant in well-draining sandy soil with at least a 20m wingspan in mind.