Zanthoxylum clava-herculis, the Hercules' club, Hercules-club, pepperwood, or southern prickly ash, is a spiny tree or shrub native to the southeastern United States.

It grows to 10–17 m tall and has distinctive spined thick, corky lumps 2–3 cm long on the bark.

The fruit is a two-valved capsule 6 mm diameter with a rough surface, and containing several small black seeds.

[5] The new trees tend to sprout below the favorite resting places of the birds, along fence rows and the edge of woods.

[6] It is known to be host to a number of insect species, including the Giant Swallowtail (Papilio cresphontes) and the leaf beetle Derospidea brevicollis.