|A planted grove of Casuarina cunninghamiana at Sunnynook Park, Auckland (Karly Garnock-Jones—photo)|
They are flowering plants, but they look very like pines until you get close. The branches are slender and have whorls of tiny leaves, so that each branchlet looks like a pine needle. Nearly all the photosynthesis probably takes place in these green slender grooved stems.
The flowers of Casuarina are wind pollinated and unisexual, in clusters on separate male and female branches, or even on separate trees. The fruits are small 1-seeded nutlets, but they're clustered together in woody pine-cone-like aggregations (the one below is about 10 mm diameter).
|Casuarina cunninghamiana fruit cluster, after the nutlets have been dispersed.|