pronounced: KER-ee-ops oss-TRAH-liss
Ceriops is derived from two Greek words, κερας (keras), a horn, and οψις (opsis), appearance – like a horn – referring to the small horn-like hypocotyl that emerges from the fruit of this genus; australis is Latin for ‘south’.
There are 3 species of Ceriops found on the coast of northern Australia, Ceriops australis, which has smooth hypocotyls, Ceriops tagal, which has ribbed hypocotyls, and Ceriops decandra, in which the peduncle length is equal to its width.
Ceriops australis a shrub or small tree growing up to 10 m with short, stocky flanged buttresses, with looped surface roots sometimes developing from the trunk, and, as mentioned above, with smooth, rounded hypocotyls. It occurs round the coast of northern Australia from Exmouth, WA, through to Moreton Bay, QLD. It is the most widely-distributed of the 3 species. As well as in Australia, it also occurs in the southern part of PNG, and through much of Indonesia.
The leaves are opposite, a glossy yellowish green in colour, obovate to obovate-elliptic in shape, with a rounded apex, 5–10 cm long and 2–4 cm long with a petiole about 2 cm long. The stipules are in pairs, and flattened.
The inflorescence is a dense cluster of 2–10 flowers; these are yellowish green to orange-red, about half a centimetre long. The petals are creamy white, and become brown with age.
The fruit is an inverted pear-shaped drupe, about a centimetre or a little more in length, and not as wide as it is long. It is seated in a sunken calyx tube with reflexed lobes. The species is viviparous, with the dispersal propagule emerging from the end of the fruit. This propagule is slender, yellowish green, and smooth (or ribbed if it is Ceriops tagal), and can grow anything up to about 15 cm long – it is usually only about 5 mm in width.
This mangrove is found as a dominant species in inner and drier mangrove stands, usually on the borders of saltpans and on the landward borders of the stands, often forming dense shrublands. The photographs were taken in such an environment in Cockle Bay. It tolerates low moisture and high salinity, but does not like wave exposure or strong winds.
The indigenous inhabitants used the timber for digging sticks, spear shafts and throwing sticks. They boiled the inner red bark and used the infusion to treat skin disorders; ashes from burnt wood were used for a similar purpose.
Caterpillars of the Emperor Moth Syntherata janetta feed on this plant.
Ceriops australis and Ceriops tagal were considered to be the same species until neighbouring trees were shown to be genetically isolated.