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Rhizophora mangle L.

Rhizophoraceae
Red mangrove

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 unpublished.


  1. Uses
  2. Folk Medicine
  3. Chemistry
  4. Description
  5. Germplasm
  6. Distribution
  7. Ecology
  8. Cultivation
  9. Harvesting
  10. Yields and Economics
  11. Energy
  12. Biotic Factors
  13. References

Uses

Timber of the mangrove is used for cabinetry, construction, piling, poles, posts, shipbuilding, and wharves. Duke (1972) notes that in Panama it is being studied for its telephone pole potential. In the Choco it is being exploited for the pulp industry. Cattle will eat mangrove leaf meal after CaCO3 has been added to raise the pH. Morton (1965) even describes a wine made from mangrove leaf and raisin. Amerindians ate the starchy interior of the fruit and hypocotyl during hard times (Morton, 1965). Dried hypocotyls have been smoked like cigars. Dried leaves have been used in Florida as a tobacco substitute. African children use the dried fruits as whistles (Irvine, 1961). In Costa Rica, concentrated bark extracts are used to stain floors and furniture, a habit shared with Africa's Ashantis. Cuna Indians make fishing lines from the brown branches. Although some have speculated that Rhizophora plantings can be used to extend or preserve precarious shores. Hou resurrects a quote suggesting the contrary "mangrove follows the silting up of a coastal area rather than precedes and initiates the accumulation of mud or other soil...it establishes itself merely on accrescent coasts" (Hou, 1958). Morton (1965), however, notes that the American Sugar Company introduced it in 1902 as a soil retainer on the mud flats of Molokai. According to Garcia-Barriga (1975) Kino de Colombia, resin from the red mangrove, has several medicinal uses.

Folk Medicine

One Cali doctor reports a cure of throat cancer, with gargles of mangrove bark (Garcia-Barriga, 1975). Reported to be astringent, emmenagogue, expectorant, hemostat, styptic, and tonic, red mangrove is a folk remedy for angina, asthma, backache, boils, ciguatera, convulsions, diarrhea, dysentery, dyspepsia, elephantiasis, enuresis, epistaxis, eye ailments, fever, filariasis, hemoptysis, hemorrhage, inflammation, jaundice, leprosy, lesions, leucorrhea, malignancies, scrofula, short wind, sores, sorethroat, syphilis, tuberculosis, uterorrhagia, and wounds (Duke and Wain, 1981; Morton, 1981).

Chemistry

Per 100 g, the leaf is reported to contain, 10.7 g protein, 3.4 g fat, 77.0 g total carbohydrate, 14.5 g fiber, and 8.9 g ash (Duke and Atchley, 1983 in ed). Per 100 g, the leaf meal is reported to contain 5.6 g H2O, 7.5 g protein, 3.6 g fat, 59.3 g NFE, 13.9 g fiber, 10.1 g ash, 1.350 mg Ca, 140 mg P, 15.2 mg Fe, 650 mg K, 600 mg b-carotene equivalent, 88 mg Mg, 30 mg Mn, 3.5 mg Cu, 0.52 mg Co, 4.3 mg Zn, 54 mg I, 13 mg thiamine, 19 mg riboflavin, 240 mg niacin, 32 mg folic acid, 5.3 mg pantothenic acid, and 46.0 mg choline (Morton, 1965). I suspect that the vitamins are off by a magnitude or two. Something is wrong with the amino acid figures as well, but perhaps the proportions are worth repeating, arginine 1.1 : lysine 0.9 : methionine 0.421 cystine 0.301 : glycine 0.801. Another analysis of the leaf tablets shows, per 100 g, 790 mg S, 8.3 mg Cu, 920 mg Na, 8.3 mg B, 224 mg chlorophyll, 0.68 mg folic acid, 5.2 ppm cobalt, and 144 ppm F (Morton, 1965). Fresh leaves contain 65.6% moisture and ca 0.1% chlorophyll. Dry bark contains 10–40% tannin, aerial roots ca 10.5%.

Description

Tree 5–20(-30) m tall, 20–50(-70) cm in diameter with arching stilt roots 2–4.5 m high. Bark gray or gray-brown, smooth and thin on small trunks, becoming furrowed and thick; inner bark reddish or pinkish. Leaves opposite or elliptical, acute at tip and base, entire, without visible veins, thick, leathery, glabrous, 6–12 cm long, 2.5–6 cm wide, shiny green upper surface, yellow-green, black-dotted underneath. Petiole 1.5–2 cm long. Stipules paired, leaving ring scar. Flowers mostly 2–4 on forked stalk 4–7 cm long in leaf axil, pale yellow, ca 2 cm across. Bell-shaped hypanthium ca 5 mm long with 4 widely spreading, narrow, leathery, pale yellow sepals 12 mm long; petals 4, 1 cm long, curved downward, whitish but turning brown, cottony on inner side; stamens 8, stalkless. Ovary inferior conical, 2-celled with 2 ovules each cell; style slender; stigma 2-lobed. Berry, ovoid, 3 cm long, dark brown. Seed 1, viviparous, becoming cigar-shaped, to 25 cm long and 12 mm in diameter (Little, 1983).

Germplasm

Reported from the African, American, and Polynesian Centers of Diversity, red mangrove, or cvs thereof, is reported to tolerate diseases, insects, pests, salt, and waterlogging (NAS, 1980a, Little, 1983). (2n = 36 in other species of Rhizophora)

Distribution

Tropical America from Bermuda through West Indies to Florida. Northern Mexico south to Brazil and Ecuador including Galapagos Islands and north-western Peru. Western Africa from Senegal to Nigeria; Angola, Melanesia, Polynesia (Little, 1983).

Ecology

Estimated to range from Tropical Moist to Rain through Subtropical Moist to Rain Forest Life Zones, red mangrove is reported to tolerate annual precipitation of 14.9 to 23.0 dm (mean of 7 cases = 18.8), annual temperature of 21.6 to 25.6°C (mean of 6 cases = 23.5), and estimated pH of 6.0 to 8.5. Mostly on brackish and saline silt of depositing shorelines.

Cultivation

Since natural regeneration is so good, this species is not often cultivated, but it has been planted, for example, to stabilize the banks of brackish aquaculture enclosures. Direct seeding yields ca 90% survival in Rhizophora and Avicennia. Air-layering and the planting of propagules have both been successful in Florida (NAS, 1980a).

Harvesting

No data available.

Yields and Economics

In Florida, red mangrove is said to fix 4 MT carbon/ha/yr (Murry and Benemann, 1981). Cannell (1982) cites data showing that Rhizophora mangle spaced at 1,100 trees/ha, averaged 7–8 m tall, and an LAI of 4.4. The stem wood and bark on a DM basis weighed 28 MT/ha, proproots 14.4 MT, the branches 12.7, the foliage 7.8, and the roots estimated at 50 MT/ha for a total standing biomass of ca 113 MT/ha. The current annual increment (CAI) of stem wood and stem bark was 3.07 MT/ha/yr, foliage 4.75 (Cannell, 1982). Litterfall was 0.84 g/m2/day wood, 1.3 g/m2/day leaves. Thus the annual foliage fall was close to 5 MT/ha/yr. These data were taken in a mangrove swamp in Puerto Rico. Standing biomass of the Pacific mangrove (R. brevistyla), from the more fertile Pacific side of Panama, was 280 MT/ha. (Duke, 1981b).

Energy

Following the phytomass files (Duke, 1981b), annual productivity is estimated to range from 5 to 20 MT/ha (with 9 reported in Puerto Pico). Wood (sp. grav. 0.9–1.2), an important source of charcoal, described as excellent for fuel and charcoal (Little, 1983).

Biotic Factors

Durable in the soil but susceptible to attack by dry-wood termites (Little, 1983). Morton (1965) reports a Cerospora (sic) leaf spot in Florida. Agriculture Handbook No. 165 notes Anthostomella rhizomorphae on leaves.

References

Complete list of references for Duke, Handbook of Energy Crops
Last update Thursday, January 8, 1998 by aw