Sonneratia ovata (PROSEA)

Plant Resources of South-East Asia Introduction

List of species

Sonneratia ovata Backer

Protologue: Bull. jard. bot. Buitenzorg, Série 3, Vol. 2: 329 (1920).

Family: Sonneratiaceae

Chromosome number: 2n = 22

Synonyms

• Sonneratia alba auct., non J. Smith (1819).

Vernacular names

• Sonneratia (En).
• Brunei: perapat
• Indonesia: bogem (Palembang), kedabu (eastern Sumatra)
• Malaysia: gedabu (Peninsular), (pedada) rogam (Sarawak)
• Cambodia: ampea, lapea
• Thailand: lamphaen.
• Vietnam: bấn ổi, bấn hôi.

Origin and geographic distribution

S. ovata is found scattered in widely separate localities from China and Thailand through Peninsular Malaysia, the Riau Archipelago, Java, and Borneo, to Sulawesi, the Moluccas, and Daru Island and Milne Bay in New Guinea. References to its occurrence in Queensland and the Northern Territory in Australia have been disclaimed. It is locally numerous, but on the whole rather rare.

Uses

The wood of S. ovata serves as firewood. As a timber it is of very limited value. S. ovata can be used to control erosion of tidal river banks. Like other Sonneratia spp., the bark contains tannin, but in amounts too small for commercial exploitation. The fruits are edible, though they taste very sour. Because of their acidity they are sometimes used as substitutes for vinegar. The fruit is also applied in poultices to relieve sprain. The fermented juice is believed to check haemorrhages.

Properties

The wood of S. ovata has been described as moderately hard to very hard and moderately heavy to heavy. Its pulping qualities have yet to be tested; the wood of the related species S. caseolaris (L.) Engler can be pulped by a sulphate process to give a pulp with strength properties similar to commercial eucalypt pulp.

The wood of Sonneratia L.f. has retained many protomyrtalean characters. One primitive feature is the rudimentary presence of scalariform and reticulate perforation plates in the wood structure. Growth rings are distinct, mainly delimited by radially flattened fibres. Parenchyma is absent, fibres are septate, with 2-3 septa per fibre.

Botany

• Columnar tree, up to 2-5(-20) m tall, with stem up to 20 cm in diameter. Stem short and usually twisted, base not buttressed, surrounded by thin, pointed, pneumatophores about 20 cm long. Bark grey, smooth to slightly fissured, lenticellate, inner bark pale brown to reddish, faintly laminated, rather watery. Sapwood pale yellow, soft. Twigs distinctly jointed above the nodes, quadrangular when young, terete with age, greyish brown.
• Leaves simple, opposite, exstipulate; petiole 2-15 mm long; blade usually ovate to orbicular or broadly ovate, 4-10 cm × 3-9 cm, base rounded or subcordate, apex broadly rounded, upper surface glossy, slightly corrugated with 9-16, fine but conspicuous lateral veins.
• Flowers bisexual, usually in terminal groups of 2-3(-4), occasionally solitary; pedicel 1-2 cm long, sometimes absent; buds broadly ovoid, apex rounded or obtuse, finely verruculose, 1.5-3 cm × 1-1.5 cm; calyx persistent, calyx tube cup-shaped, tapering abruptly into a stalk-like base, ribbed segments usually 6, ovate-triangular, 13-15 mm long, inner surface markedly reddish cream at base; petals absent or vestigial; stamens many, filaments about 2 cm long, white, anthers yellow; ovary 10--15-celled, style about 2.5 cm long.
• Fruit an indehiscent, flattened globose berry, resting on the calyx-tube, 3-5 cm in diameter, 2-3 cm thick, dark green when young turning yellowish-green when ripe.
• Seeds numerous, rounded, irregular, about 5 mm long, embedded in foul-smelling pulp; embryo straight.

Hybrids between S. ovata, S. alba J. Smith and S. caseolaris (L.) A. Engler have been found in the estuary of Brunei, where they grow together. Normally they are ecologically separated, S. ovata growing closest to the land-side. Diagnostic field characteristics for S. ovata are the broadly ovate leaves without mucro, the verruculose calyx surface, the appressed calyx lobes in fruit, the absence of petals, the white filaments and the rounded irregular seeds. Its flowers are ephemeral and open at sunset, lasting for only one night; stamens fall off in the early morning. Bats and nectar-feeding birds are the pollinators. In Papua New Guinea, S. ovata flowers from March to October, and fruits are ripe in April-December. In Vietnam it flowers in March-April and bears mature fruits in June-July.

Ecology

S. ovata is occasionally found on the banks of tidal creeks and rivers, on muddy soils inundated only by spring tides. Fruits float, so water is the normal means of dispersal. It is found as individual trees, scattered among other mangrove species, such as Excoecaria agallocha L. S. ovata has never been found forming pure stands similar to S. alba and has also never been recorded from coral reefs.

Agronomy

Although S. ovata mostly grows wild, it is cultivated for its fruits and as an ornamental in some villages in coastal Sarawak. Propagation is by seed.

Prospects

Although the wood of S. ovata is used as firewood, it is not sought after. S. ovata may be used to control erosion along tidal river banks. S. ovata will probably remain of very limited economic importance.

Literature

• Ashton, P.S., 1988. Manual of the non-dipterocarp trees of Sarawak. Vol. 2. Dewan Bahasa dan Pustaka, Kuala Lumpur, Malaysia. p. 380.
• Backer, C.A. & van Steenis, C.G.G.J., 1951. Sonneratiaceae. In: van Steenis, C.G.G.J. (Editor): Flora Malesiana, Series 1, Vol. 4. Noordhoff-Kolff, Jakarta, Indonesia. pp. 280-289.
• Duke, N.C. & Jackes, B.R., 1987. A systematic revision of the mangrove genus Sonneratia (Sonneratiaceae) in Australasia. Blumea 32: 277-302.
• Muller, J. & Hou-Liu, S.Y., 1966. Hybrids and chromosomes in the genus Sonneratia (Sonneratiaceae). Blumea 14: 337-343.
• Rao, R.V., Sharma, B., Chauhan, L. & Dayal, R., 1987. Reinvestigation of the wood anatomy of Duabanga and Sonneratia with particular reference to their systematic position. IAWA (International Association of Wood Anatomists) Bulletin (new series) 8(4): 337-345.
• Voon Boon Hoe, Sim, P. & Chin Thian Hon, 1988. Sayur-sayuran dan buah-buahan hutan di Sarawak [Vegetables and fruits from the forest in Sarawak]. Department of Agriculture, Sarawak, Malaysia. 55 pp.

Main genus page

• Sonneratia (Timbers)

Authors

• R.H.M.J. Lemmens (general part, selection of species) (Timbers)

• B. Othman (Auxiliary plants)