black locust: Robinia pseudoacacia (Fabales: Fabaceae (Leguminosae)): Invasive Plant Atlas of the United States

black locust	USDA PLANTS Symbol: ROPS U.S. Nativity: Native Habit: Hardwood Trees
Robinia pseudoacacia L.

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Taxonomic Rank: Magnoliopsida: Fabales: Fabaceae (Leguminosae)
Synonym(s): false acacia, yellow locust
Native Range: U.S.- East: southern and central Appalachians from northern GA to PA and Ozarks- AR, MO and OK, ()
Black locust is a deciduous tree that, while native to parts of the United States, has spread to and become invasive in other parts of the country. Trees grow from 40-100 ft. (12-30 m) in height. Trees grow upright in forests, but develop an open growth form in more open areas. Leaves are pinnately compound with 7-21 small, round leaflets per leaf. Leaflets are 1.5 in. (4 cm) long. A pair of long, stipular spines is found at the base of most leaves. Flowering occurs in the spring, when flowers develop in 8 in. (20.3 cm) long clusters. The showy, fragrant, white to yellow flowers give way to a smooth, thin seed pod that is 2 to 4 in. (5.1-10.2 cm) in length. The bark of black locust is light brown, rough, and becomes very furrowed with age. Black locust is native to the Southern Appalachians, the Ozarks, and other portions of the Midsouth, but is considered an invasive species in the prairie and savanna regions of the Midwest where it can dominate and shade those open habitats.

Identification, Biology, Control and Management Resources

Fire Effects Information System - USDA Forest Service
Silvics of North America - USDA Forest Service
Element Stewardship Abstract - The Nature Conservancy
Weeds Gone Wild: Alien Plant Invaders of Natural Areas - Plant Conservation Alliance
Invasive Plant Atlas of New England - University of Connecticut

Selected Images from Invasive.org

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Diagram or Graphic; 1. Branchlet with flowering and leafy shoots. Pea-flower shaped (»papilionaceous«) flowers open in pendulous terminal racemes. Odd-pinnate compound leaves with short petioluled leaflets. - 2. Shoot with ripe pods (f) and pendulous leaflets (B) during night. Fruits are many-seeded flat pods. - 3. Ripe seed as seen from two aspects. - 4. Seedling with cotyledons (c) and first ordinary leaves. - 5. Winter-branchlet - terminal bud is missing. Buds are small, naked, hidden inside the leaf scars and typically located between two modified spiny stipules. After Hempel & Wilhelm, 1889. Photos and explanations from the book: Zelimir Borzan. "Tree and Shrub Names in Latin, Croatian, English, and German, with synonyms", University of Zagreb, 2001. Zelimir Borzan, University of Zagreb, Bugwood.org Additional Resolutions & Image Usage	Foliage; Jan Samanek, State Phytosanitary Administration, Bugwood.org Additional Resolutions & Image Usage	Foliage; Paul Wray, Iowa State University, Bugwood.org Additional Resolutions & Image Usage	Foliage; James H. Miller, USDA Forest Service, Bugwood.org Additional Resolutions & Image Usage
Foliage; James H. Miller, USDA Forest Service, Bugwood.org Additional Resolutions & Image Usage	Bark; Paul Wray, Iowa State University, Bugwood.org Additional Resolutions & Image Usage	Feature(s); Stipular Spines Leslie J. Mehrhoff, University of Connecticut, Bugwood.org Additional Resolutions & Image Usage	Flower(s); Paul Wray, Iowa State University, Bugwood.org Additional Resolutions & Image Usage
Flower(s); Jan Samanek, State Phytosanitary Administration, Bugwood.org Additional Resolutions & Image Usage	Flower(s); Jan Samanek, State Phytosanitary Administration, Bugwood.org Additional Resolutions & Image Usage	Flower(s); Bill Cook, Michigan State University, Bugwood.org Additional Resolutions & Image Usage	Flower(s); Leslie J. Mehrhoff, University of Connecticut, Bugwood.org Additional Resolutions & Image Usage
Flower(s); Jan Samanek, State Phytosanitary Administration, Bugwood.org Additional Resolutions & Image Usage	Flower(s); Leslie J. Mehrhoff, University of Connecticut, Bugwood.org Additional Resolutions & Image Usage	Fruit(s); Leslie J. Mehrhoff, University of Connecticut, Bugwood.org Additional Resolutions & Image Usage	Fruit(s); Jan Samanek, State Phytosanitary Administration, Bugwood.org Additional Resolutions & Image Usage
Fruit(s); fruits remaining in spring from previous year Jan Samanek, State Phytosanitary Administration, Bugwood.org Additional Resolutions & Image Usage	Fruit(s); Paul Wray, Iowa State University, Bugwood.org Additional Resolutions & Image Usage	Fruit(s); fruit and seeds Richard Old, XID Services, Inc., Bugwood.org Additional Resolutions & Image Usage	Fruit(s); Jan Samanek, State Phytosanitary Administration, Bugwood.org Additional Resolutions & Image Usage
Fruit(s); fruit and seeds Paul Wray, Iowa State University, Bugwood.org Additional Resolutions & Image Usage	Feature(s); Clonal Growth Leslie J. Mehrhoff, University of Connecticut, Bugwood.org Additional Resolutions & Image Usage	Tree(s); Leslie J. Mehrhoff, University of Connecticut, Bugwood.org Additional Resolutions & Image Usage	Tree(s); in flower Jan Samanek, State Phytosanitary Administration, Bugwood.org Additional Resolutions & Image Usage
Tree(s); Chris Evans, River to River CWMA, Bugwood.org Additional Resolutions & Image Usage	Seedling(s); Brian Lockhart, USDA Forest Service, Bugwood.org Additional Resolutions & Image Usage	Sapling(s); Yound sapling growing within a 50 year old pine stand. Poland Gil Wojciech, Polish Forest Research Institute, Bugwood.org Additional Resolutions & Image Usage	Seed(s); Steve Hurst, USDA NRCS PLANTS Database, Bugwood.org Additional Resolutions & Image Usage
Diagram or Graphic; Britton, N.L., and A. Brown. 1913. Illustrated flora of the northern states and Canada. Vol. 2: 375. USDA PLANTS Database, USDA NRCS PLANTS Database, Bugwood.org Additional Resolutions & Image Usage

EDDMapS Distribution:
This map is incomplete and is based only on current site and county level reports made by experts and records obtained from USDA Plants Database. For more information, visit www.eddmaps.org

State(s) Where Reported invasive.
Based on state level agency and organization lists of invasive plants from WeedUS database.

Native Alternatives:
Cladrastis kentukea (Kentucky yellowwood) Gleditsia triacanthos (honeylocust) Gymnocladus dioicus (Kentucky coffeetree) Parkinsonia florida (blue paloverde) Populus tremuloides (quaking aspen)	More Information on Native Plants at: www.beplantwise.org PlantWise is a partnership between the National Park Service, Lady Bird Johnson Wildflower Center, The Garden Club of America and The National Invasive Species Council to prevent harmful invasive plants from invading natural areas.