Acorus americanus, the American Sweet Flag, is an emergent wetland plant native to the northern United States and Canada. This perennial plant has bright green blade-shaped leaves that arise directly from the rhizomes and sheath into each other at the base. Additionally the blades have 2-6 raised veins, and a swollen center when viewed in cross section. The foliage has a citrus-like spicy aromatic quality, and can be used to flavor beer. It is a flowering plant with inconspicuous flowers that are arranged on a lateral spadix (a thickened, fleshy axis) and the fertilized flowers produce berries with a jelly inside. This plant is protected as a state endangered species in Pennsylvania.