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Avicennia germinans L.

Syn: Avicennia nitida Jacq.
Avicenniaceae
Black mangrove

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 unpublished.


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

Uses

Information on Avicennia species is confused, due to the difficulty, historically at any rate, of distinguishing the species. Regarding the timber useage, Burkill quotes Foxworthy, "altogether it a very unsatisfactory wood—the least useful of the mangrove-swamp woods—and the tree is usually considered as a weed in the swamps." Little (1983) says it is used for crossties, marine construction, piers, posts, utility poles, and wharves. Ashes are added to water as a soap substitute. Bark is used for tanning. Smoke from the wood is said to constitute an effective mosquito smudge (Duke, 1972). Flowers are a major source of honey.

Folk Medicine

According to Hartwell (1967–1971), the resin is used in folk remedies for tumors in the West Indies. Reported to be astringent, insect repellent, rubefacient, and tonic, black mangrove is a folk remedy for diarrhea, dysentery, hemorrhage, hemorrhoids, rheumatism, swellings, throat ailments, tumors, and wounds (Duke and Wain, 1981; Garcia-Barriga, 1975). Salvadorans use the resin for chest complaints and sore throat. Bahamans believe it restores lost vitality (Morton, 1981) and use it in baths for rheumatism. Colombians say gargling with the bark decoction alleviates cancer of the larynx and malignant ulcers of the throat (Garcia-Barriga, 1975).

Chemistry

Per 100 g, the seed is reported to contain 354 calories, 9.8 g H2O, 5.6 g protein, 0.5 g fat, 81.3 g total carbohydrate, 4.0 g fiber, 2.8 g ash, 207 mg Ca, and 117 mg P. Leaves contain on a zero-moisture basis, 10.7% protein, 4.0% fat, 69.2% total carbohydrate, 23.9% fiber, and 15.7% ash (Duke and Atchley, 1983).

Toxicity

Fruits, though edible after processing, are said to be toxic raw (Little, 1983).

Description

Evergreen shrub or small tree 3–12(-25) m high; trunk 30–60 dm in diameter. Masses of small air roots 15–45 cm long sometimes hang from upper part of large trunks. Pneumatophores often rise 5–10 cm from the long horizontal roots. Bark dark gray or brown and smooth on small trunks, becoming dark brown, fissured, scaly, and thick. Leaves opposite, lanceolate or narrowly elliptical, 5–11 cm long, 2–4 cm wide, acute or blunt at tip, entire, thick, leathery. Fine hairs giving a grayish hue to foliage; both surfaces often with scattered salt crystals and salty taste. Petiole 3–15 mm long. Spikes or panicles headlike, upright at and near ends of twigs. Flowers several, crowded, sessile, 6 mm long, 10 mm across. Calyx cup-shaped, deeply 5-lobed; corolla tubular, hairy, white but yellowish at base, with 4 slightly unequal spreading, rounded, or notched lobes, stamens 4, 5 mm long in notches of corolla tube near base; pistil with imperfectly 4-celled ovary, slender style, and 2-forked stigma. Capsule elliptical, flattened, 2.5–3 cm long, often splitting into 2 parts. Seed 1, large, flattened, often germinating on tree (Little, 1983).

Germplasm

Reported from the Middle and South American Centers of Diversity, black mangrove, or cvs thereof, is reported to tolerate disease, insects, pests, salt, and waterlogging. Seems to tolerate prolonged flooding.

Distribution

Along coasts of tropical America. Atlantic Coast; Bermuda, Bahamas, West Indies, southeastern US, northern Florida, southeastern Texas, northern Mexico southward on Atlantic Coast to Brazil and on Pacific Coast to Ecuador including Galapagos Islands and northwestern Peru. The same or very closely related species on coasts of western Africa. Not widely planted or introduced elsewhere (Little, 1983).

Ecology

Estimated to range from Tropical Dry to Wet through Subtropical Dry to Wet Forest Life Zones, black mangrove is reported to tolerate annual precipitation of 8.7 to 20.6 dm (mean of 4 cases = 14.1) and annual temperature of 25.3 to 26.6°C (mean of 4 cases = 25.9). Common in mangrove swamp forests, mainly on the landward side in brackish water in mud flats of tidal zones of protected silty shores and at the mouths of rivers.

Cultivation

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

Harvesting

Since this mangrove can regrow rapidly from buds beneath the bark along the trunk and branches, it is said to suffer little from removal of much of the branchwood (NAS, 1980a).

Yields and Economics

Good mangrove stand can show annual productivity of 10–20(-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 above ground productivity. Because of the heaviness of the wood, a cubic meter of mangrove is generally more valuable than other species.

Energy

Generalizing about the genus Avicennia, Burkill (1966) notes that when freshly cut, the heartwood floats, but the sapwood sinks. "It gives indifferent firewood...not liked because it cannot be split. It is used, however, when better is not easily procurable. It burns smoulderingly. The fisher-folk like it for smoking fish, to which it is said to give an agreeable flavor. It is used, also, for smoking rubber" (Burkill, 1966). Still in Latin America the wood is valued "mainly for fuel, charcoal" (Morton, 1981). "Wood used for fuel and charcoal, burning with intense heat" (Little, 1983).

Biotic Factors

No data available.

References

Complete list of references for Duke, Handbook of Energy Crops
Last update December 29, 1997