Beach Casuarina or Coastal She-oak

The Beach Casuarina or Coastal She-oak (Casuarina equisetifolia) is a common plant on Australian tropical beaches. It can occur as a shrub or a tree. It is often the first plant to colonise this basically unfriendly habitat and, although wispy and fairly insubstantial in growth, it provides welcome shade. It looks as if it might be some kind of pine with long drooping needles but in fact the ‘pine needles’ are thin articulated branchlets. In the close-up photographs below you can see that the branchlets resemble the stems of the Horsetail plants (Equisetum spp.) – primitive plants dating back to the Carboniferous Period from which we know them in fossil form in coal measures and similar rocks – they even share similar Latin names.

The leaves of the Beach Casuarina are barely noticeable, being very small indeed and growing with even spacing along the stems from which the branchlets arise. You can see these scale-like leaves if you click to enlarge, for example, the photograph in the gallery below Beach Casuarina 7. The plant has unobtrusive and separate male and female flowers. Male flowers are white at the end of the branchlets while the female flowers are small and red and grow on special side branchlets. The fertilised female flowers develop into small, hard spiky fruits, with some similarity to pine cones [and also strikingly reminiscent in outline shape of the hairstyle favoured by Lisa Simpson and her baby sister Maggie].