Robinia pseudoacacia

Tree to 25 m, the twigs and peduncles puberulent, becoming subglabrous; stipules commonly modified into spines 1 cm; lfls 7-19, oval or elliptic, 2-4 cm; racemes drooping, many-fld, 1-2 dm; fls white, fragrant, 1.5-2.5 cm; cal finely hairy, the upper lip truncate or broadly notched; ovary glabrous; fr 5-10 cm; 2n=20. Native from Pa. and s. Ind. to Okla., s. to Ga. and Ala., and often escaped from cult. n. to N.S. and Que. May, June.

Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.

©The New York Botanical Garden. All rights reserved. Used by permission.

From Flora of Indiana (1940) by Charles C. Deam

This species has been freely planted since pioneer times and has escaped in all parts of the state. It was, no doubt, a native in the southeastern part of the state near the Ohio River.

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Indiana Coefficient of Conservatism: C = 1

Wetland Indicator Status: FACU

Deam (1932): Black locust wood is somewhat lighter than white oak, but is 34 per cent stiffer and 45 per cent stronger. The remarkable qualities added to its durability in contact with the ground make it one of the most desirable trees for forest planting. The wood has been used principally for posts, ties, tree nails, etc. The black locust when grown close together usually grows to 8-12 inches in diameter. There are, however, specimens that have grown in the open that are almost three feet in diameter. The pioneers used it extensively for ornamental planting, and it has escaped from such planting in all parts of the state. It propagates easily by root shoots which is the principal mode of spreading, except where the seeds fall on exposed soil.... It is adapted to all kinds of soils, except for a wet one. It prefers a well drained soil and seems to grow as fast in a loose clay as in a black loam.... The locust has the habit of having the branch ending in a fork, this giving rise to one or more very large side branches. The best management requires that the large side branches be removed as soon as they are noted, and one part of the terminal forks be cut off. 

The locust until recently gave great promise of being an important tree for planting sterile, washed, and erodes slopes, on which it usually thrives and in many cases grows thriftily. However, report from all parts of the state show that locust groves wherever planted are being killed by the locust body borer. The locust has also been attacked by the twig borer, bag worm, and the leaf miner. At present there are no known economic means of controlling these destructive pests....