Where seen? This mangrove tree is considered rare, although
some shores such as Chek Jawa and Pulau Semakau may have large numbers
of them. Large numbers are also seen in a lagoon in the middle of
the Sentosa Serapong golf course. According to Hsuan Keng, these were
scattered in our mangroves including Pasir Ris, Pulau Pawai, Ulu Pandan
and Tanjung Gul. According to Davison, small populations are found
in Pasir Ris Park, St John's Island, Pulau Semakau, Pulau Tekong,
Sentosa and Western Catchment. According Giersen, it grows on a variety
of ground, preferring banks of tidal rivers but also pioneering species
on the coast and landward margins of mangroves. It occurs primarily
in Southeast Asia and has been found in tropical Australia as well
as Taiwan and northern Australia.
Features: Tree with single or
multiple-trunks up to 10m tall. Aerial roots from the lower branches.
Stilt roots up to 3m long, often forming extensive loops to some distance
from the trunk. Bark grey to black and fissured.
Leaves eye-shaped (8-15cm long), shiny green, leathery, smaller than
R. mucronata, with tiny evenly distributed black spots on the
underside. Stipule usually pale or yellowish.
Flowers (1-2cm) 4-8 or more on long branching stalks (2-4cm) drooping
down from the branch. Bract egg-shaped white hard thick. Petals thin,
delicate with dense woolly marginal hairs. The petals fall off soon
after blossoming. Style (0.4-0.6cm) longer than in R. mucronata.
The flowers are believed to be wind pollinated.
The fruit looks like a brown, upside down pear (2-3cm) and is crowned
by short persistent sepals. The fruit is small relative to the sepals,
when compared to R. mucronata. The cylindrical hypocotyl is
not as pimply as that of R. mucronata and generally shorter
(less than 30cm).
Sometimes mistaken for Bakau
kurap (Rhizophora mucronata) which has larger leaves and
longer, more pimply propagules. The two species can only be distinguished
with certainty by looking at the details of the flowers. R. stylosa
has a longer style.
Human uses: According to Giesen,
it is used as timber, firewood and to produce charcoal. The Australian
aborigines use it to make boomerangs, spears and ceremonial objects.
The fruit is used to make a light wine and a concoction to treat blood
in the urine.
Status and threats: It is listed
as 'Vulnerable' on the Red List of threatened plants of Singapore.
It is threatened by habitat destruction and oil spills.
stilt roots extending outward.
Pulau Semakau, May 07
on long branching stalks.
Pulau Semakau, Mar 09
Fruit not so large compared to sepals.
St John's Island, Aug 09
with long style,
more visible without petals.
Hantu, Sep 13
pasir on Singapore shores
- Hsuan Keng,
S.C. Chin and H. T. W. Tan. 1990, The
Concise Flora of Singapore: Gymnosperms and Dicotyledons.
Singapore University Press. 222 pp.
P. B., 1986. The
Botany of Mangroves
Cambridge University Press. USA. 419 pp.
G.W. H. and P. K. L. Ng and Ho Hua Chew, 2008. The Singapore
Red Data Book: Threatened plants and animals of Singapore.
Nature Society (Singapore). 285 pp.