American germander is a robust perennial plant with a fibrous root system, forming clumps up to 3 ft (90 cm) tall. The upright squarish stems have small side branches, and send out rhizomes at the base. The leaves are opposite, stemmed lower on the plant and unstemmed on the upper sections of the stalk. They are ovate or lanceolate, deeply veined and coarsely toothed, up to 5 in (13 cm) long and 2.5 in (6 cm) wide. The terminal inflorescence contains numerous whitish or pale lilac lipped flowers with large shelf-like lower lips. The fruits contain four pitted seeds covered with white hairs.