Acanthus is a genus of about 30 species of flowering plants in the family Acanthaceae, native to tropical and warm temperate regions of the Old World, with the highest species diversity in the Mediterranean region and Asia. Common names include Acanthus and Bear's breeches.
The genus comprises herbaceous perennial plants, rarely subshrubs, with spiny leaves and flower spikes bearing white or purplish flowers. Size varies from 40 cm, up to 2 m tall. An example of one such plant is the Shrimp Plant which can be found in the state of Florida in the United States.
The foliage is the basis of a style of architectural ornamentation; see acanthus (ornament).