Virginia Tech Weed Identification Guide

Perilla Mint or Beef-steak Plant: Perilla frutescens

Weed Description:  An erect herb with distinctive green or purplish-green leaves with toothed margins.  These plants emit a distinctive minty odor, especially when mature.  Perilla mint is primarily a weed of pastures, hay fields, fencerows, and roadsides.  This plant is extremely toxic to all kinds of cattle, sheep, and horses.
Leaves:  Arranged oppositely along the stem, green in color, most often with a distinct purple tinge.  Individual leaves are oval-shaped, approximately 2 to 5 inches long, 1 1/2 to 4 inches wide.   Leaves occur on petioles, have distinctly toothed margins and emit a minty odor when crushed.
perilla8-3.jpg (160661 bytes) Stems: Erect, from 1/2 to 2 feet in height.
Flowers:  Many flowers occur in terminal clusters giving the mature plant a 'bottle-brush' appearance.  Individual flowers are small, white to whitish-purple in color, hairy, with an upper lip that is 3-toothed and a lower lip that is 2-toothed.
pmint9-20.jpg (164161 bytes) Identifying Characteristics:  The distinctive minty odor and oval, green to purple leaves with toothed margins are all characteristics that help in the identification of perilla mint.  Hophornbeam copperleaf (Acalypha ostryifolia) has similar leaves and growth habit, but does not have the characteristic minty odor and greenish purple leaves like those of perilla mint.