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Bakau
Rhizophora sp.
Family Rhizophoraceae
updated
Aug 09
Where seen? These trees with arching stilt roots are commonly
seen in many of our mangroves. Burkill describes Rhizophora
as making up 70-90% of the mangrove stock in Malaya. He describes
them as growing so densely 'as to make almost pure forest' behind
a 'protective belt' of Avicennia which faces the open sea.
Features: Leaves eye-shaped (8-15cm
long), shiny green with tiny evenly distributed black spots on the
underside: these are cork warts. The form of the flower depends on
the species, usually with a hard and thick bract. The petals are thin
and fall off soon after blossoming. The fruit is brown and a long
propagule eventually develops on the parent tree. The tree has stilt
roots emerging in arches from the lower trunk, and prop roots may
grow downwards from branches. Rhizophora means "root bearer"
in Greek.
According to Tomlinson, the flowers of most species of Rhizophora
are wind pollinated.
Human
uses: According to Burkill, the trees are most used for
firewood. One great advantage "in the eyes of the firewood seller"
is the ease in which the timber can be split. So the pedlar taking
it from door to door can split it to meet the needs of the buyer.
It also burns evenly and produces good quality heat, even comparable
to coal. It was also used to produce charcoal. It is also valued as
a source of tannins. In fact, the use of mangrove trees in tanning
leather has been recorded by early Arab traders. Besides tanning leather,
the bark was originally used by fishermen to toughen their fishing
lines and ropes. The tree is much in demand for piling and house frames
built near mangroves and swamps. As well as for building fishtraps.
Status and threats: R. stylosa
is listed as 'Vulnerable' on the Red List of endangered plants in
Singapore. |
Pulau Semakau,
Mar 09

Underside
of the leaf.
Pulau Semakau, Mar 09
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Chek
Jawa, Oct 09
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Prop
roots from branches, stilt roots from trunk.
Pulau Semakau, Mar 09
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Often with a 'skirt' of many prop roots.
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With looping stilt roots that can
extend some distance from the tree.
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Flower on very short stalks.
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Flowers on long branching stalks.
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Flowers on long branching stalks.
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Shorter style
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Longer style.
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Fruit on very short stalk,
almost stuck to the branch.
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Fruit on stalks.
Fruit large compared to sepals.
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Fruit on stalks.
Fruit not so large compared to sepals.
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Usually a bent hypocotyl.
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Very long hypocotyl.
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Hypocotyl not so long.
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Links
Other
references
- Hsuan Keng,
S.C. Chin and H. T. W. Tan. 1990, The
Concise Flora of Singapore: Gymnosperms and Dicotyledons
.
Singapore University Press. 222 pp.
- Corners,
E. J. H., 1997. Wayside
Trees of Malaya: in two volumes
.
Fourth edition, Malayan Nature Society, Kuala Lumpur. Volume 1:
1-476 pp, plates 1-38; volume 2: 477-861 pp., plates 139-236.
- Tomlinson,
P. B., 1986. The
Botany of Mangroves
Cambridge University Press. USA. 419 pp.
- Davison,
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.
- Corners,
E. J. H., 1997. Wayside
Trees of Malaya: in two volumes
.
Fourth edition, Malayan Nature Society, Kuala Lumpur. Volume 1:
1-476 pp, plates 1-38; volume 2: 477-861 pp., plates 139-236.
- Burkill,
I. H., 1993. A
Dictionary of the Economic Products of the Malay Peninsula
.
3rd printing. Publication Unit, Ministry of Agriculture, Malaysia,
Kuala Lumpur. Volume 1: 1-1240; volume 2: 1241-2444.
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