Northern Prairie Wildlife Research Center
MINT FAMILY (Labiatae or Lamiaceae)
IND. STATUS: OBL
FIELD CHARACTERISTICS: A rhizome-producing, perennial herb, usually only 5-15 cm. high (rarely to 80 cm.). The square stems are erect with opposite leaves. Leaves are stalked or nearly so and are hairless above; at least the lower leaves are pinnately toothed at least halfway to the midrib. The small, white flowers form dense clusters in the leaf axils. Flowers lack stalks, have two stamens, and are in bloom from July through September. The petals extend beyond the calyx-lobes. The calyx-lobes are at least 1-2 mm. long and extend beyond the nutlets at maturity; are narrowly triangular with the width at the base less than half the length; and have a prominent midvein. Bugleweeds (Lycopus spp.) are not strongly aromatic.
L. americanus may be confused with L. uniflorus and L. virginicus, both of which have blunt, triangular calyx-lobes that lack a prominent midvein. The calyx-lobes of these latter two species are equal to or shorter than the nutlets at maturity. Note, all three species can occur together.
ECOLOGICAL NOTES: Common bugleweed is one of our most common wetland herbs. In addition to sedge meadows, this species occurs in marshes, calcareous fens, fresh (wet) meadows, wet to wet-mesic prairies, floodplains, poorly drained fields, and ditches. It is also called cut-leaved water horehound.
SOURCE: Fassett (1957); Gleason and Cronquist (1991); and Swink and Wilhelm (1994).