Robinia pseudoacacia (black locust)

Robinia pseudoacacia

Photo courtesy Joseph DiTomaso

Robinia pseudoacacia (black locust) is a deciduous tree (family Fabaceae) that grows to 100 feet tall. It is found throughout California below 6,300 feet. Historically planted as a landscape tree, black locust has escaped cultivation and become invasive in California and elsewhere. It can grow on a wide range of sites, but grows best on rich, moist, limestone-derived soils. It does not do well on heavy or poorly drained soils, although it appears to be tolerant of some flooding. Through root sprouts and seedling establishment, black locust creates large stands that displace native vegetation. Its seeds, leaves, and bark are toxic to humans and livestock.

Cal-IPC Inventory rating: Limited

Cal-IPC Resources on Robinia pseudoacacia

• California Invasive Plant Inventory Assessment Form (pdf) - Information gathered by Cal-IPC on the impacts, rate of spread, and distribution of invasive plants in California. Does not include management information.
• Species account from Invasive Plants of California's Wildlands - Includes biology and management information.
• Cal-IPC News - Articles from our quarterly newsletter. Each issue is available as a pdf. List of articles on Robinia pseudoacacia.
• Cal-IPC Symposium Proceedings - Presentations and papers from our annual Symposium. List of articles on Robinia pseudoacacia.
• Don't Plant a Pest! - Select your region to find non-invasive alternatives to ornamental species. Also see our statewide number on trees.

Cal-IPC News Articles

• Connick, S. and M. Gerel (2005). Don't sell a pest: A new partnership to prevent plant invasions through horticulture. Cal-IPC News. 13: 4-5,14.

Cal-IPC Symposium Proceedings

• Connick, S. and M. Gerel (2004). Partnering to prevent invasions of plants of horticultural origin. California Invasive Plant Council Symposium 2004. Ventura, CA.
• Hunter, J. C., J. C. Sterling, et al. (2003). The abundance and distribution of non-native woody species in Sacramento Valley riparian zones. California Invasive Plant Council Symposium 2003. Kings Beach, CA.
• Reichard, S. H. (1996). What traits distinguish invasive plants from non-invasive plants? California Exotic Pest Plant Council Symposium '96. San Diego, CA.

Other Resources on Robinia pseudoacacia

• USDA PLANTS database - Federal database with information on identification and distribution, and links to websites in individual states.
• Jepson Online Interchange for California Flora - Information on taxonomy, biology, and distribution from the UC Berkeley Jepson Herbarium.
• CalFlora - Distribution information by county based on submitted observations and herbarium specimens.
• The Nature Conservancy Management Summary - Information compiled by TNC land managers. Photos included for some species.
• CalPhotos - Images of plants taken mostly in California.
• Natural Resource Projects Inventory - State database with information on resource management projects throughout California. Query by the species of interest.

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