Carolina Nature

Trees, Shrubs, and Woody Vines of North Carolina

Black Locust (Robinia pseudoacacia)

Plantae>Magnoliophyta>Magnoliopsida>Fabales>Fabaceae>Robinia pseudoacacia L.

Black Locust (Robinia pseudoacacia) flowers

A common, medium-sized tree of edges and waste places. Native to the Appalachians, where it is abundant and planted as an ornamental further east. It frequently escapes from cultivation and is now thoroughly naturalized in the Piedmont and Coastal Plain.

The fragrant flowers, produced in late April, are quite stunning.

Duke campus, Durham, NC 4/24/2003.

Black Locust (Robinia pseudoacacia) leaves

The pinnately compound leaves, with many elliptical leaflets, are distinctive. The most similar species is Honeylocust (Gleditsia triacanthos), which has yellow flowers and much larger thorns and pods.

Black Locust (Robinia pseudoacacia) leaves

Grayson Co., VA 5/30/2009.

Black Locust (Robinia pseudoacacia) leaves

Grayson Co., VA 5/30/2009.

Black Locust (Robinia pseudoacacia) leaves

Grayson Co., VA 5/30/2009.

Black Locust (Robinia pseudoacacia) flowers

Haywood Co., NC 5/9/08.

Black Locust (Robinia pseudoacacia) spines

Black Locust is armed with two spines at the base of each leaf or leaf bud.

Haywood Co., NC 5/10/08.

Black Locust (Robinia pseudoacacia) spines

Haywood Co., NC 5/10/08.

Black Locust (Robinia pseudoacacia) spines

Carroll Co., VA 4/11/10.

Black Locust (Robinia pseudoacacia) spines

Carroll Co., VA 4/11/10.

Black Locust (Robinia pseudoacacia) spines

Carroll Co., VA 4/11/10.

Black Locust (Robinia pseudoacacia) spines

Durham, NC 4/24/2003.

Black Locust (Robinia pseudoacacia) tree

Blacksburg, Montgomery Co., VA 7/13/07.

Black Locust (Robinia pseudoacacia) bark

The bark of older trees is deeply furrowed and has diamond-patterned ridges.

Blacksburg, Montgomery Co., VA 7/13/07.

Black Locust (Robinia pseudoacacia) bark

Blacksburg, Montgomery Co., VA 7/13/07.

More information:
PCA Alien Plant Working Group
Trees of Alabama and the Southeast
US Forest Service Silvics Manual
Virginia Tech Dendrology

Recommended Tree, Shrub, and Woody Vine Identification Guides