Ceriops decandra (PROSEA)
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Introduction |
Ceriops decandra (Griffith) Ding Hou
- Protologue: Fl. Males., Ser.1, Vol. 5(4): 471 (1958).
- Family: Rhizophoraceae
- Chromosome number: 2n= 36
Synonyms
- Ceriops roxburghiana Arn. (1838).
Vernacular names
- Brunei: tengar
- Indonesia: tengar (Javanese), palun (Ambon), bido-bido (Halmahera)
- Malaysia: tengar (Peninsular), landing-landing (Sarawak)
- Philippines: malatangal (Tagalog), tungung (Bisaya), tungug (Ibanag)
- Singapore: tengar
- Burma: ka-pyaing
- Cambodia: smaè
- Thailand: kapuulong (Phetchaburi), prong khaao (Samut Sakhon), samae manoh (Satun)
- Vietnam: dzà.
Origin and geographic distribution
The genus Ceriops Arn. was once more widely distributed than it is today. For example, it was probably present in Europe in the Eocene; both Ceriops and some other Rhizophoraceous genera appear in the European fossil record before they appear in that of South-East Asia. Clearly the ranges of the species have changed. Thus although C. decandra is now centred in South-East Asia it is not certain that it originated in this region. Its current range extends from the Indus delta in Pakistan around the coast of India and across the Bay of Bengal to Burma, and thence through Indo-China, Thailand and South-East Asia to Papua New Guinea. It also occurs locally in north-eastern Australia. In South-East Asia it is found in Peninsular Malaysia, the Philippines, Borneo, Java, Sulawesi, the Lesser Sunda Islands, the Moluccas, and New Guinea. It has not yet been collected from Sumatra, but recently it has been reported from there.
Uses
In the past the bark of this species was an important source of high quality tannin, and although its use for this purpose has waned in recent years, it is still used locally. Both bark and leaves are used for tanning in South-East Asia and India. The sap of the bark yields a black dye used in the "batik" industry, and a decoction of the bark is used to treat haemorrhages. The large scale exploitation of this species for posts, poles, firewood and charcoal has been widespread, and still occurs in places. The branches are used for tool handles, and bent ones for boat ribs. Some wood of this species has been chipped for pulp.
Production and international trade
There are no reliable figures for the volumes of this species felled each year, nor for the proportions of the annual volume cut which are used for different purposes. Figures given in literature often refer to several mangrove species.
Properties
The bark contains 25-37% tannin. A tannin extract imparts a reddish colour to leather and makes it somewhat harsh and thick. It is often mixed with other tanning materials, such as myrobalans from fruits of Terminalia chebula Retz. and bark of Acacia nilotica (L.) Willd. ex Del., which modify the colour of the leather. The extract is used for heavy leather. A mixture of bark and leaves gives a better leather of lighter colour than the bark alone. The development of acidity in the tanning liquors, resulting in stiffness of the leather, can be eliminated by quick tanning of the hides, or by adding alkaline phenate. Mangrove tannin is generally very soluble and develops a minimum of insoluble matter, with the result that it produces very little sludge in the tanning liquor. The basic components of the tannin are 3',4',5,7-tetrahydroxyflavan-3,4-dioles, which ranks the tannin in the proanthocyanidins. Extracts from the bark contain about 19% of mucous substances, composed of arabinose, rhamnose and galactose.
The wood is moderately resistant to decay and has a life in contact with the ground of about 2 years. It is pale whitish-yellow when freshly cut but turns orange-brown on exposure to air, and is usually somewhat less heavy than the wood of C. tagal (Perr.) C.B. Robinson. When dry the wood burns with a hotter flame than that of most other mangrove species. Anatomically the wood is similar to that of C. tagal, but with rather larger and fewer vessels per mm2.
Description
- A straight columnar tree, usually of small to medium size, but under favourable conditions attaining a height of 35 m and a diameter of the trunk of 35 cm, with a relatively narrow crown and short basal buttresses which appear to develop from the fusion of clusters of stilt roots; roots superficial, spreading radially, with small knobby and/or looping pneumatophores in wet sites; bark whitish or pale grey, smooth but slightly fissured towards the base, peeling around the buttresses; branches conspicuously jointed with swollen nodes.
- Leaves opposite, clustered at the end of the twigs, coriaceous, obovate to elliptic-oblong, 4.5-10 cm × 2.5-6 cm, cuneate at base, rounded or subemarginate at apex, glabrous and glossy; petiole 1-2.5 cm long, with lanceolate, 1.5-2.5 cm long deciduous stipules at base.
- Flowers in head-like, condensed up to 5-flowered cymes in leaf-axils at the upper part of a branch, 5-6-merous, 5-6 mm long, with deeply lobed calyx and white ca. 2.5 mm long petals, fringe-like divided at the apex; stamens twice the number of calyx lobes, anthers longer than filaments; ovary semi-inferior, 3-celled.
- Fruit an ovoid-conical berry, 1-1.8 cm long, with persistent erect or ascending calyx lobes, blunt basally, warty at the apex.
- Seeds viviparous. Hypocotyl club-shaped, protruding below the fruit while this is still attached to the tree, 9-15 cm long, occasionally longer (e.g. in New Guinea), slightly fluted.
Growth and development
Trees tend to flower periodically and synchronously over wide areas, but seasonally under seasonal climates. Fruiting is often prolific and single trees may subtend several thousands of seedlings at the same time. Seedlings take up to 12 months to develop, with shorter times in wet equatorial regions. Seedlings fall from the trees when the hypocotyls become detached from the cotyledonary tubes. Subsequent development involves a seedling being stranded and lodged in the mud, followed by the rapid production of adventitious roots which serve to anchor it. Most seedlings are slender and small and cannot survive long periods while floating in the water, and consequently are not as successfully dispersed over long distances as those of other mangrove Rhizophoraceae. However, once "planted" in the shade of other trees their rate of establishment is very high.
Ecology
C. decandra is most common in tidal forest in high rainfall regions, where characteristically, it grows in the middle to landward parts of the mangrove swamp. Here it is commonest in sites flooded by virtually all high tides, i.e. where the soil surface is below mean high water level. It develops best immediately behind the forest strip lining rivers, and on the slightly higher muddy tidal flats behind, between rivers and creeks. In these sites fresh water is in regular supply and salinity never exceeds that of normal sea water. Locally this species is gregarious, forming a slender pole forest, but it is most often associated with species of Avicennia L., Bruguiera Lamk and Rhizophora L. However, its station is not constant, and it occurs on the landward fringes of some mangrove swamps.
Handling after harvest
For tanning purposes the bark of older Ceriops trees is peeled off, because the tannin content increases with age. The bark may be used directly in the tannery, or tanning extracts may be prepared from it, marketed as blocks or powder. Often a mixture of bark from several mangrove species (Ceriops, Rhizophora, Bruguiera species etc.) is used for preparing a tanning extract which is called "mangrove cutch".
Prospects
The outlook for the uses of this species depend largely on the exploitation and reafforestation of mangroves, as is the case with other mangrove species.
Literature
- Crevost, Ch. & Pételot, A., 1941. Catalogue des produits de l'Indochine. Tome 6. Tannins et tinctoriaux. Gouvernement général de l'Indochine, Hanoi. pp. 32-33 + fig.
- Hou, D., 1958. Rhizophoraceae. In: van Steenis, C.G.G.J. (Editor): Flora Malesiana, Series 1. Vol. 5. pp. 471-472, fig. 24 f-h.
- Howes, F.N., 1962. Tanning materials. In: von Wiesner, J. (Editor): Die Rohstoffe des Pflanzenreichs. 5th ed. J. Cramer, Weinheim, Germany. pp. 178-184.
- Rollet, B., 1981. Bibliography on mangrove research, 1600-1975. Unesco Paris. xxviii + 479 pp.
Authors
R.H. Hughes & S. Sukardjo
