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Catalpa spp. |
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Family: Bignoniaceae |
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Catalpa |
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The genus Catalpa is composed of 11
species native to North America [2], West Indies [5], and temperate Asia (China
to Tibet) [4]. The name catalpa is the Native American (Cherokee) name for this
tree.
Catalpa bignonioides*-beantree, beau-tree,
candle-tree, catawba, catawba-tree, cigartree, common catalpa, Indian bean,
Indian cigartree, southern catalpa
Catalpa longissima*-(Jamaica and Haiti)
French oak, Haitian oak, Jamaica oak, mastwood, yokewood
Catalpa speciosa*-candle-tree, catawba,
cigartree, hardy catalpa, Indian bean, Indian cigartree, northern catalpa, shawnee-wood, western
catalpa, western catawba
*commercial species
The following description is for the North
American species.
Distribution
Catalpa is native to the central eastern United
States, but is naturalized throughout the United States and Canada.
The
Tree
Catalpa trees are often planted as street trees
and for shade in yards, but most often for their showy flowers. The tree has
opposite, simple, entire leaves. The flowers are bisexual and formed in
branched clusters. The fruits are large bean-like structures, resembling
cigars. Catalpa trees can reach 100 ft (30 m) in height and 3 ft (1 m) in
diameter. The bark is thick, with reddish-brown scales.
The
Wood
General
The wood is similar for both North American
species. The sapwood is narrow and gray, while the heartwood is a grayish
brown, tinged with lavender. The wood has a faint aromatic odor and no
characteristic taste. It is ring porous, straight grained, light and soft. It
can be confused with ash.
Mechanical Properties (2-inch standard)
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Compression |
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Specific gravity |
MOE x106 lbf/in2 |
MOR x103 lbf/in2 |
Parallel x103 lbf/in2 |
Perpendicular x103 lbf/in2 |
WMLa in-lbf/in3 |
Hardness lbf |
Shear x103 lbf/in2 |
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Green |
.38 |
.84 |
5.2 |
1.45 |
.32 |
7.9 |
410 |
.68 |
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Dry |
.42 |
1.21 |
9.4 |
2.74 |
.57 |
9.6 |
550 |
1.13 |
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aWML = Work to maximum load.
bReference (98). cReference (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 |
4.9 |
3.9 |
1.6 |
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Radial |
2.5 |
2.0 |
.8 |
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Volumetric |
7.3 |
5.8 |
2.4 |
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aBirch
shrinks considerably during drying. References: 0% MC (98), |
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Kiln Drying Schedulesa
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Stock |
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Condition |
4/4, 5/4, 6/4 |
8/4 |
10/4 |
12/4 |
16/4 |
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Standard |
T8-C4 |
T6-C3 |
T6-C3 |
T5-C3 |
T3-B1 |
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aReferences
(6, 86). |
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Working Properties: Catalpa works very well with
hand and machine tools, although it requires care to sand well.
Durability: Very resistant to heartwood decay
when the wood is in contact with the soil.
Preservation: No information available at this
time.
Uses: Fence posts and rails, general
construction, interior finish, handles, picture frames, cabinetry and fuel
wood.
Toxicity: No information available at this time.
Additional Reading and References Cited (in parentheses)
29. Elias, T.S. 1980. The complete trees of
North America, field guide and natural history. New York: van Nostrand Reinhold
Company.
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.
59. Markwardt, L.J.; Wilson, T.R.C. 1935.
Strength and related properties of woods grown in the United States. Tech.
Bull. 479. 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.
90. Summitt, R.; Sliker, A. 1980. CRC handbook
of materials science. Boca Raton, FL: CRC Press, Inc. Vol. 4.