Perilla frutescens (L.) Britton

Taxonomy and Stalk Characteristics

Perilla frutescens (L.) Britton, commonly called perilla, is an annual plant that grows 60–90 cm (24–35 in) tall, with hairy, square stalks.

Leaf Arrangement and Shape

Its leaves are arranged oppositely, measure 7–12 cm (3–4+1⁄2 in) long and 5–8 cm (2–3 in) wide, have a broad oval shape with pointed tips, serrated (saw-toothed) edges, and long leafstalks.

Leaf Coloration

The leaves are green, and occasionally have purple tints on their undersides.

Flowering Time and Inflorescence

Perilla produces flowers in racemes at the ends of branches and the main stalk in late summer.

Calyx Structure

Its calyx is 3–4 mm (1⁄8–5⁄32 in) long, made up of three upper sepals and two hairy lower sepals.

Corolla Structure

The corolla is 4–5 mm (5⁄32–3⁄16 in) long, with a lower lip longer than the upper lip.

Stamen Characteristics

Of its four stamens, two are long.

Fruit Characteristics

The fruit is a schizocarp 2 mm (1⁄16 in) in diameter, with a reticulate (net-like) pattern on its outer surface.

Seed Appearance

Perilla seeds are globular, can be soft or hard, and range in color from white, grey, and brown to dark brown.

Seed Weight and Lipid Content

1000 perilla seeds weigh approximately 4 g (1⁄8 oz), and seeds contain 38 to 45 percent lipid by content.

Native Distribution

This plant is native to Bangladesh; India, specifically the Eastern and Western Himalayas and Northeast India; Nepal; Myanmar; China, specifically South Central China and Southeast China; Thailand; Laos; Vietnam; Java; Taiwan; Japan; Korea; and Russia, specifically Primorsky Krai and Khabarovsk Krai.

Introduced Distribution

It has been introduced to other regions including Inner Mongolia, Cambodia, parts of Europe (Germany, Romania, Ukraine, and South European Russia), several U.S. states, and the Canadian province of Ontario.

Weed Classification

After spreading across the United States, P. frutescens has been classified as a weed there.

Livestock Toxicity

While perilla is widely grown as an edible plant for humans, it is toxic to cattle, other ruminants, and horses.

Cattle Poisoning Symptom

In grazing cattle, plant ketones from perilla cause acute respiratory distress syndrome, also known as "panting disease".

Contact Health Risk

People handling perilla leaves or oil may develop contact dermatitis.

Consumption Health Risk

Consumption of large quantities of perilla seeds has caused cases of anaphylaxis.