Trema lamarckianum, Lamarck's trema, West Indian nettle tree, or pain-in-the-back is a plant species in the genus Trema of the family Cannabaceae. It is a small evergreen shrub that is native of Florida and the West Indies. It has several common names such as pain-in-back, cabrilla and Lamarck trema. It is 6 m tall growing all year.