Beefsteak-plant, Perilla Mint

Perilla frutescens

Lamiaceae (Mint family)

Description

Beefsteak-plant is a coarse, aromatic annual, often purple or tinged with purple. Its branching, erect, square stem is usually 30 to 45 inches tall, but may be as tall as 5 feet. The opposite, simple leaves are oval and pointed, have a pronounced serrate or incised edge and may be up to 6 inches long. The small white or purple flowers are arranged in terminal spikes up to 6 inches long arising from the leaf axils. Ornamental varieties often have a stronger purple tinge and a ruffled edge to the leaves.

Habitat

Beefsteak-plant was introduced from East Asia, escaped cultivation and is widespread across the eastern United States. These plants require ample water and are found in east Texas and into Arkansas, Oklahoma and Louisiana. Perilla mint can grow in dense stands and is usually found at the edge of damp woods and in open spots along streams and seepage areas (part sun/part shade).

Toxic Agent

Perilla mint is known to contain several toxic furan ketones. These compounds are toxic to the lungs of cattle, sheep, horses and laboratory animals. The toxins are present throughout the entire plant, but are concentrated in the inflorescence (flower cluster); most cases of poisoning occur after flowering, in late summer or early fall. Hay containing the mature plant is potentially toxic, but does not pose a great hazard.

Signs of Livestock Ingestion

Clinical signs are: labored breathing, open-mouth breathing, expiratory grunt, and death. Affected animals appear to have pneumonia and suffer from oxygen deprivation because of pulmonary edema and emphysema. Attempts to move or treat them should be slow and easy.

Management Strategies

Atropine can aid recovery, but the stress of treatment may make it counterproductive. Do not graze pastures with a large amount of perilla mint in the late summer or fall when other forage is short.