Heritiera littoralis (Malvaceae, previously classified as Sterculiaceae) was selected as Plant of the Month during our March outing, against some strong competition from the fascinating mix of species at the Palmetum.
Although this species typically grows in low to moderate salinity conditions at the landward edge of mangrove forests, two specimens are thriving beside the Palmetum’s freshwater lagoon.
The small flowers, covered in fine hairs, develop into large keeled fruits that are tough and buoyant when ripe, well adapted for long-distance dispersal by water – see photo at the bottom.
Heritiera littoralis is distinctive from a distance on breezy days because upturned leaves flash intermittently like small mirrors within the dark green canopy, in keeping with the species’ common name, Looking-glass mangrove. On calm days, the leaves create a silvery-white glow under the canopy.
There is another large specimen in cultivation at Anderson Park, as Greg reminded us. If you have a seasonally wet and boggy corner of the garden, where it’s difficult to find a suitable plant, Heritiera littoralis might be worth a try. Just keep an eye out for those distinctive floating fruits when they wash up on the beach.
Botanical details are available in the Australian Tropical Rainforest Plants database.