Bruguiera gymnorrhiza (L.) Savigny

Syn.: Bruguiera conjugata Auct.
Rhizophoraceae
Burma mangrove

Source: James A. Duke. 1983. Handbook of Energy Crops. unpublished.

Uses
Folk Medicine
Chemistry
Toxicity
Description
Germplasm
Distribution
Ecology
Cultivation
Harvesting
Yields and Economics
Energy
Biotic Factors
References

Uses

The heavy wood (sp. grav. 0.87–1.08) is durable but hard to saw and work. It is used for construction, furniture, houseposts, and pilings (Little, 1983). Thousands of tons of Bruguiera wood chips are exported annually from Indonesia, Sabah, and Sarawak for pulp and for rayon manufacture (NAS, 1980a). Fruits are eaten, but not when anything better is available. More often, they are chewed as astringent with the betel quid. Chinese in Java make a sweetmeat therefrom. Dutch Indians use the bark to flavor raw fish. The leaves and peeled hypocotyls are eaten in the Moluccas after soaking and boiling (Hou, 1958). The phlobaphene coloring matter is used in China and Malaya for black dye (Burkill, 1966). In South Africa, the tree has been planted to stabilize dunes and in freshwater swamps.

Folk Medicine

Reported to be astringent (Duke and Wain, 1981), the bark is used for diarrhea and fever in Indonesia (Perry, 1980). Cambodians use the astringent bark for malaria (Burkill, 1966).

Chemistry

In Burma, leaves may contain 18.3% H₂O, 13.5% tannin; outer cortex (small trees) 14.6 and 7.9, outer cortex (large trees) 14.2 and 10.8; twig bark 13.1 and 14.8, bole bark (small trees) 16.3 and 31.7, while the bole bark of large trees contains 12.5% H₂O, 42.3% tannin. Bark contains from ca 4–32% tannin, 12.77–53.12% according to Watt and Breyer-Brandwijk (1962) and the Wealth of India (C.S.I.R., 1948–1976).

Toxicity

Eating too much (bark) is dangerous (Burkill, 1966).

Description

Evergreen tree 8–25(-35) m high, with straight trunk 40–90 cm in diameter, buttressed at base, and with many upright pneumatophores rising to 45 cm from long horizontal roots. Bark gray to blackish, smooth to roughly fissured, thick; inner bark reddish. Leaves opposite, elliptical, 9–20 cm long, 5–7 cm wide, acute at both ends, entire, without visible veins, thick, leathery, glabrous. Petiole 2–4.5 cm long. Flowers single in leaf axile 3–4 cm long, usually drooping on stalk of 1–2.5 cm, red to yellowish or cream-colored, with red to pink-red bell-shaped hypanthium. Calyx with 10–14 very narrow, leathery lobes. Petals 10–14, 13–15 mm long, white turning brown, each with 2 narrow lobes ending in 3–4 bristles. Stamens 2, nearly hidden, at base of each petal. Pistil with inferior 3–4-celled ovary, each cell with 2 ovules, style slender; stigma with 3–4 short forks. Berry drooping, ovoid or turbinate, 2–2.5 cm long. Seed 1, viviparous, finally 1.5–2 cm in diameter (Little, 1983).

Germplasm

Reported from the Hindustani, Africa, Australian, and Indonesian-Indochina Centers of Diversity, Burma mangrove, or cvs thereof, is reported to tolerate alkali, disease, high pH, insects, pest, salt, shade, waterlogging (NAS, 1980a; Little, 1983). (2n = 18)

Distribution

Tropical South and East Africa, Madagascar, Seychelles, Sri Lanka, southeastern Asia, Ryukyu; throughout Malaysia to Philippines, Australia, Micronesia, and Polynesia. Introduced into Hawaii (Little, 1983).

Ecology

Estimated to range from Tropical Moist to Rain through Subtropical Moist to Rain Forest Life Zones, Burma mangrove is reported to tolerate annual precipitation of 10 to 80 dm, annual temperature of 20 to 26°C, and pH of 6.0 to 8.5. One of the largest trees in the Malayan mangroves, usually on drier well-aerated soils toward the landward side, often dominating, with occasional stems >35 m tall. It is probably the longest lived of the mangroves. It can stand "any amount of shade" (Hou, 1958). Mostly on brackish or saline silts of depositing shores and marshes.

Cultivation

According to the NAS (1980a), planting is usually not needed because natural regeneration is so successful. In Avicennia and Rhizophora, direct seeding results in ca 90% survival.

Harvesting

Mostly harvested from natural stands. Species of Rhizophoraceae, growing only from the tips of the branches, are often killed by indiscriminate lopping of branches (NAS, 1980a). After felling, its regeneration is often very scant and there is danger of overgrowth by Acrostichum (but once seedlings have established themselves, the "fern acts rather as a nurse, forcing the seedling up.") (Hou, 1958).

Yields and Economics

Good mangrove stand can show annual productivity of (-25) MT/ha/yr, but for firewood purposes, I would reduce that to 10–20(-25) m³ /ha/yr, figuring that at optimal rather than average. Litterfall may account for 1/3–1/2 of aboveground productivity. Because of the heaviness of the wood, mangrove is generally more valuable than other species.

Burkill, J.H. 1966. A dictionary of economic products of the Malay peninsula. Art Printing Works, Kuala Lumpur. 2 vols.
C.S.I.R. (Council of Scientific and Industrial Research). 1948–1976. The wealth of India. 11 vols. New Delhi.
Duke, J.A. and Wain, K.K. 1981. Medicinal plants of the world. Computer index with more than 85,000 entries. 3 vols.
Hou, D. 1958. Rhizophoraceae. p. 429–493. In: van Steenis, C.G.G.J. (ed.), 1955–1958, Flora Malesiana. series 1, vol. 5, P. Nordhoff Ltd., Republic of Indonesia.
Little, E.L. Jr. 1983. Common fuelwood crops: a handbook for their identification. McClain Printing Co., Parsons, WV.
N.A.S. 1980a. Firewood crops. Shrub and tree species for energy production. National Academy of Sciences, Washington, DC.
Perry, L.M. 1980. Medicinal plants of east and southeast Asia. MIT Press, Cambridge.
Watt, J.M. and Breyer-Brandwijk, M.G. 1962. The medicinal and poisonous plants of southern and eastern Africa. 2nd ed. E.&S. Livingstone, Ltd., Edinburgh and London.

Complete list of references for Duke, Handbook of Energy Crops

Last update Tuesday, December 30, 1997