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Avicennia spp. |
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Family: Avicenniaceae
(Verbenaceae) |
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Black Mangrove |
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The genus Avicennia contains about 15
species which grow along tropical and subtropical shores. It is commonly
included with the family Verbenaceae. The genus Avicennia was dedicated in honor
of Abu Sina, Latinized as Avicennia (980—1036 AD), of Bokhara, Arab physician and
philosopher.
Avicennia alba-baen
Avicennia germinans-black mangrove, black-tree, blackwood,
honey mangrove,
mangle blanco, saltbush
Avicennia marina-blackwood, mangle nero, mangle
prieto, manglecito, parwa
Distribution
This genus
grows in pure, dense stands on mud flats along the coast and estuaries, in
brackish coastal swamps, and on river banks along lower brackish parts.
The Tree
The tree
sometimes reaches a height of 75 ft (23 m), although normally only 25 ft
(8 m), with a 2-ft (0.6-m) diameter. Towards the northern end of its limit (Dog
Island, Florida) it is shrubby. Black mangroves have long heavy roots which
grow extensions (pneumatophores) that aid in gas exchange and coincidentally
trap silt to extend the shoreline. Seeds mature and germinate on the tree and
then fall to the mud.
The Wood
General
The sapwood of
mangrove is wide, yellow—gray to brown—yellow. The heartwood is dark yellow—brown
to very dark brown with an oily appearance. The luster is low and the wood has
no distinct odor or taste. The grain is irregular and interlocked, and the
texture is coarse and uneven. The wood may contain a yellow powdery substance
called lapachol. The bole is 20 to 40 ft (6 to 12 m) long and unbutressed, but
it is swollen due to numerous pneumatophores (aerial roots). The woods of all
species are practically identical, with concentric, anastomosing layers of
secondary phloem (bast).
Mechanical Properties
(2-inch standard)
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Compression |
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Specific gravity |
MOE x106 lbf/in2 |
MOR lbf/in2 |
Parallel lbf/in2 |
Perpendicular lbf/in2 |
WMLa in-lbf/in3 |
Hardness lbf |
Shear lbf/in2 |
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Green |
0.83 |
1.55 |
11,100 |
4,940 |
1,870 |
12.3 |
1,700 |
1,370 |
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Dry |
0.83 |
2.09 |
16,400 |
8,340 |
2,360 |
17.9 |
— |
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aWML = Work to maximum load.
Reference (59). |
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Drying and
Shrinkage
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Type of shrinkage |
Percentage of
shrinkage |
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0% MC |
6% MC |
20% MC |
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Tangential |
9.7 |
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Radial |
6.2 |
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Volumetric |
15.6 |
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aThe wood
air-dries well; kiln drying requires a slow |
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Kiln Drying
Schedule: No information available at this time.
Working
Properties: The wood saws well, but it is not easy to work with because of the
interlocked grain. It glues well, but nail holes must be prebored to prevent
splitting.
Durability: Very
susceptible to termite and marine borer attack. Resistance to impregnation
variable.
Preservation:
No information available at this time.
Uses: Used in
the round (poles and posts for netting), underground foundations (pilings),
pulp (soda process), fuel, charcoal, tannin from bark.
Toxicity: No
information available at this time.
Additional
Reading and References Cited (in parentheses)
4, 14, 29, 45, 55, 68, 74, 80, 101.
4.Berni, C.A.;
Bolza, E.; Christensen, F.J. 1979. South American timbers. The characteristics,
properties and uses of 190 species. Melbourne, Australia: Commonwealth
Scientific and Industrial Research Organization, Division of Building Research.
14.Cellai, G.C.
1967. Atlante micrografico dei legni dell’Africa orientale. 60. Avicennia marina (Forsk.). Firenze,
Italy: Vierhapper, Verbenaceae. Grafica Toscana.
29. Elias, T.S.
1980. The complete trees of North America, field guide and natural history. New
York: van Nostrand Reinhold Company.
45.Japing, H.W.
1957. Tests about the most important mechanical and physical properties of 41
Surinam wood species. Mededeling 122. Afdeling Tropische Producten 46.
Amsterdam, The Netherlands: Royal Tropical Institute.
55. Little, Jr.,
E.L. 1979. Checklist of United States trees (native and naturalized). Agric.
Handb. 541. Washington, DC: U.S. Department of Agriculture, Forest Service.
U.S. Government Printing Office.
68. Panshin,
A.J.; de Zeeuw, C. 1980. Textbook of wood technology, 4th ed. New York:
McGraw-Hill Book Co.
74. Record,
S.J.; Hess R.W. 1943. Timbers of the new world. New Haven, CT: Yale University
Press.
80. Sattar,
M.A.; Bhattacharjee, D.K.. 1987. Physical and mechanical properties of Sundri (Heritiera fomes) and Baen (Avicennia alba). Bull. 10. Chittagong,
Bangladesh: Government of the People's Republic of Bangladesh, Forest Research
Institute, Timber Physics Series.
101. Vink, A.T.
1965. Surinam timbers. 3d ed. Paramaribo, Surinam: Surinam Forest
Service.