Rhizophora apiculata Blume
Family
Rhizophoraceae
Synonyms
Rhizophora candelaria DC., Rhizophora conjugata Arnott, non L.
Vernacular Names
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Malaysia |
Bakau minyak, bakau tandok, bakau akik. |
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Brunei |
Bakau minyak, bakau. |
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Indonesia |
Bakau minyak (general), bako (Javanese), babakoan laut (Sundanese). |
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Papua New Guinea |
Abia (Gulf Province), bahkweh (Northern Province), pan a (Central Province). |
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Philippines |
Bakauan (lalaki), uakatan (Tagalog), bakhau (Samar). |
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Singapore |
Bakau minyak, redtree. |
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Myanmar |
Pyoo. |
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Cambodia |
Kaông ka:ng nhi:. |
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Thailand |
Kongkang-bailek, kongkang. |
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Vietnam |
C[aa]y d[uw][ows]c. |
Geographical Distributions
Rhizophora apiculata is commonly found in most mangrove swamps in tropical Asia, from the delta of the Indus in Pakistan to Vietnam and Hainan. It occurs throughout the Malesian region and southwards to the Tropic of Capricorn in Queensland, and eastwards as far as New Caledonia and Ponape (Micronesia).
Description
Rhizophora apiculata is an evergreen tree, that can grow up to over 30 m tall and with trunk up to 50 cm in diameter. It is generally much smaller in exploited forests. Its bole is 10-12 m. The stem is supported by numerous, lateral, much branched stilt roots. The aerial roots sometimes develop from the lower branches. The taproot is usually abortive. Its branching primarily is sympodial. The bark is grey, almost smooth or with vertical fissures. The branchlets are swollen at the nodes. They are solid and pithy.
The leaves are arranged decussate and rosette-like at the end of twigs. The stipules are 4-8 cm long, lance-shaped , conspicuous and caducous. The reddish petiole is 1.5-3 cm long. The blade is entire, elliptical-oblong to sublanceolate, measuring 7-18 cm x 3-8 cm, leathery, green and shiny. The apex is acute to apiculate, with wedge-shaped base, distinct above veins, obscure beneath, hairless with minute and scattered black corky warts on the lower surface. It is visible on the older or dried leaves.
The inflorescence is axillary (leaf scar below the leaf rosette) and 2-flowered. The peduncle is 0.5-1.5 cm long and thick. The bracteoles at the base of flower are cup-shaped. They are fleshy and slightly crenate. The yellow flowers are bisexual and sessile. The sepal is deeply 4-lobed, coriaceous, accrescent and reflexed in fruit. The lobes are ovate, measuring 10-14 mm x 6-8 mm, concave, acute, brown-yellow to reddish and persistent. The receptacle is with a disk. There are 4 free petals which are lance-shaped, measuring 8-11 mm x 1.5-2 mm, membranous, hairless and early caducous. There are at most 12 stamens which are sessile, with anthers 6-7.5 mm long, acute, multi-loculate and open with a large ventral valve. The ovary is 1.5-3.5 mm long, semi-inferior, and 2-celled where the superior part is enclosed by the disk and bluntly conical. The style is 0.5-1 mm long and 2-lobed.
The brown fruit is an ovoid or inversely pear-shaped berry, measures 2-3.5 cm long and rather rough. The hypocotyl is cylindrical to club-shaped, measures up to 40 cm x 1.2 cm, often slightly curved, more or less blunt, smooth and shining. It is green tinged with red.
Ecology / Cultivation
Rhizophora apiculata is the most common mangrove species. It grows gregariously in swamps flooded by normal high tide, on deep soft mud of estuaries, often consolidated and sheltered from surf and currents by pioneer species of Avicennia L. and Sonneratia L.f. R. apiculata avoids hard soils and develops well in perhumid regions where it can form almost pure stands, sometimes in association with Bruguiera spp. or R. mucronata. It does not occur in fresh water swamps. It is killed by frost and by extended periods of near-freezing temperatures.
Line Drawing / Photograph
References
- Plant Resources of South-East Asia No.11: Auxiliary plants.
