Natongtong (Tall-stilt Mangrove)
- Natongtong are used for soil stabilization, coastal protection, wildlife/marine habitat for marine fauna, as well as for timber and fuelwood.
- Mangroves improve water quality in nearshore environments.
- Seeds in mangroves germinate on the parent tree.
- Mangrove forests provide windbreaks along the coast and can be used to seek
Rhizophora apiculata
Mangroves are associated with wet, muddy and silty sediment. This species of mangrove has both aerial prop roots and stilt root which are designed to resist large waves and tropical storms. They are used to stabilise soil, to protect the coastline from storms, and to provide habitat for marine species. They also improve the water quality in nearshore environments. Parts of the plant can be used for traditional medicines and mangrove forests can be used as a sanctuary during cyclones. Natongtong grows up to 40 m in height, though it commonly reaches 5 to 8 m. The bark is grey to dark grey and heavily fissured, although it can occasionally be red-brown and smooth.
Leaves
Leaves are light or dark green, opposite, simple, egg-shaped and leathery with a distinct sharp pointed tip that is 1 to 7 mm long. The upper leaf is smooth and shiny. Mature leaves are 6 to 19 cm long and 3 to 10 cm wide. The leaf stalks are reddish.
Flowers
The flower clusters have few to many joint and one to many buds per cluster. The sepals of the flower, that encloses the petals and protects the flower bud, are typically pale yellow at maturity. The flower buds are egg-shaped, changing from green (immature) to pale yellowish green (mature). Buds are 1 to 2 cm long and 1 cm wide. There are generally four petals that are pointed at both ends to linear, with a creamy white colour, and are 10 mm long and 2 mm wide. Petals are arranged in a cross-shaped pattern. The stamens are pale yellow.
Fruit
At maturity, the fruit are pear-shaped, elongate, with a smooth brown surface. The smaller end points down. Mature fruit are located in leaf axils 8 nodes down from the apical (end of leaf distant from the branch) shoot. Seeds are hidden in the mature fruit. One to occasionally two seedlings are produced from the fruit, emerging from the smaller end while the fruit is still attached to the parent plant.
- First fully open flower
- Less than half the tree is in full flower
- More than half the tree is in full flower
- All of the tree is in full flower
- No flowering
- Less than half the tree has fruit
- More than half the tree has fruit
- All of the tree has fruit
- No fruit
- Green fruit present
- Ripened fruit present
When to Look
- Year round
- The flowering period is generally August to December in the southern hemisphere.
- Leaf emergence is mostly November to February.
- Leaf fall occurs during the wet summer period, October to February.
- Fruiting is primarily from November to January.
Where to Look
- This mangrove species often found in mid-lower estuary in larger riverine estuaries and embayments.
- The intertidal wetland zone, 0 – 6 m in elevation.
- They thrive under a range of intertidal conditions, from near freshwater to full strength seawater.
- Tolerate a range of soil types and flooding regimes.
Similar Species
Natongtong is the Bislama word for mangrove, so it encompasses many species. There is also the potential for verbal confusion with Wild Natongtong, which is actually Cryptocarpa turbinate, a forest species.
Stilt mangroves can be distinguished from red mangroves species by the presence of a spiked, sharp pointed tip at the leaf apex. Other Rhizophora species have an under surface with unevenly spread cork wart spots.
Other stilt mangroves:
R. mucronata and R. stylosa have slender bracts at the base of mature buds (other stilt mangroves have bracts almost as wide or wider than their length). R. apiculate differs in that it has swollen (wider than long), corky brown bracts, one flower cluster joint, and node position of mature buds and flowers in leaf axils at 6-11 nodes down from the apical shoot. R. apiculata is more prevalent in estuaries influenced by larger and more continuous freshwater flows. Hybridization between the species is known.
