Robinia is a genus of about 10 species native to eastern North America and Mexico. The genus Robinia is dedicated to Jean Robin (1550-1629) and his son Vespasian Robin (1579-1662), herbalists to kings of France and first to cultivate locust in Europe.
Robinia kelseyi Kelsey locust
Robinia neomexicana locust, Mexican locust, New Mexican locust, New Mexican robinia, New Mexico locust, southwestern locust, thorny locust, western locust
Robinia pseudoacacia* acacia, bastard locust, black laurel, black locust, common locust, common robinia, false acacia, false black locust, green locust, honey locust, locust, peaflower locust, post locust, red locust, robinia, shipmast locust, white locust, white honey-flower, yellow locust
Robinia viscosa black locust, clammy-bark locust, clammy locust, false acacia, honey locust, red locust, red-flowering locust, rose acacia, rose-flowering locust
* commercial species
Distribution: Black locust is native to the Appalachian Mountains from Pennsylvania to northern Georgia and Alabama and to the Ozark Mountains of southern Missouri, Arkansas and eastern Oklahoma. Also in southern Illinois and Indiana. Black locust has been extensively naturalized in the United States and Canada.
The Tree: Black locust reaches a height of 100 ft (30 m), with a diameter of 3 ft (1 m).
General Wood Characteristics: The sapwood of black locust is a creamy white, while the heartwood varies from a greenish yellow to dark brown. The wood turns a reddish brown when exposed to the air. The wood is often confused with osage orange (Maclura pomifera). It has a high density and decay resistance. It shows slight shrinkage and stays in place well. Black locust is very strong in bending and is one of the hardest woods in America. Its shock resistance is almost that of hickory (Carya spp.).
Weighta
Weight
Moisture Specific lb/ft3 kg/m3
content gravity
Green 0.66 58 929
12% 0.69 48 769
Ovendry 0.71 NA NA
aReferences: specific gravity, green and
12%, (98); specific gravity, ovendry,
(59); weight, (59).
Mechanical propertiesa
Property Green Dry
MOE 1.85 106 12.755 GPa 2.05 106 14.135 GPa
lbf/in2 lbf/in2
MOR 13.8 103 95.151 MPa 19.4 103 133.763 MPa
lbf/in2 lbf/in2
C| | 6.80 103 46.886 MPa 10.2 103 70.329 MPa
lbf/in2 lbf/in2
C 1.16 103 7.998 MPa 1.83 103 12.618 MPa
lbf/in2 lbf/in2
WML 15.4 106.183 18.4 126.868
in-lbf/in3 kJ/m3 in-lbf/in3 kJ/m3
Hardness 1,570 lbf 6,983.36 N 1,700 lbf 7,561.60 N
Shear| | 1.76 103 12.135 MPa 2.48 103 17.099 MPa
lbf/in2 lbf/in2
aReference (98).
Drying and shrinkagea
Percentage of shrinkage
(green to final moisture
content)
Type of 0% MC 6% MC 20% MC
shrinkage
Tangential 7.2 5.8 2.4
Radial 4.6 3.7 1.5
Volumetric 10.2 8.2 3.4
aReferences: 0% MC, (98); 6% and 20%
MC, (90).
Kiln drying schedulea
4/4, 5/4, 8/4 10/4 12/4 16/4
Condition 6/4 stock stock stock stock
stock
Standard T6-A3 T3-A1 NA NA NA
aReferences (6, 86).
Working Properties: Black locust is difficult to work with hand tools, but it turns well on a lathe and nails well. It has no distinctive odor or taste.
Durability: Rated as exceptionally resistant to heartwood decay.
Preservation: No information available at this time.
Uses: Fencing, insulator pins, furniture, mine timbers, treenails for ships. The trees are used in strip mine reclamation because of their ability to survive the acid conditions and for their nitrogen-fixing roots.
Toxicity: There are reports of dermatitis from the wood (4, 9, 17).
Additional Reading: 20, 29, 41, 55, 60, 68, 74, 55, 66, 68, 74, 79. 28, 29, 42, 43, 44, 48, 50, 55, 56, 68, 72, 73, 74, 79, 92, 97, 102. 74, 75, 77, 99, 106. 101. 82, 104.