Family: Pokeweed Family (Phytolaccaceae)
Other Names: Phytolacca decandra, American cancer, American nightshade, American spinach, bear's grape, cancer-root, coakum, garget, inkberry, inkweed, pigeonberry, poke, pokeberry, pokeroot, pokeweed, red-ink plant, skoke berry, Virginia poke.
Origin and Distribution: Common pokeweed is native to the eastern half of the U.S. The distribution of this species has not been mapped in Ohio, but it appears to be widespread and is continuing to invade reduced-tillage fields. Common pokeweed prefers low, rich, somewhat disturbed, gravelly soils, and can be found in pastures, roadsides, fencerows, open woods and wood borders.
Plant Description: Common pokeweed is a large, bushy, herbaceous perennial that sometimes resembles a small tree, growing up to 10 feet in height. It is characterized by an enormous taproot, smooth succulent red-purple stems, large lance-shaped leaves and grape-like clusters of dark purple berries in the fall. This species reproduces from seeds.
- Root system - Common pokeweed produces a large, fleshy, white taproot (4 to 6 inches in diameter).
- Seedlings & Shoots - Cotyledons are egg- to lance-shaped, pointed and often tinged with red on the underside and on the leaf stalk. The first true leaves are egg-shaped to oval. Stems and leaves of young shoots are smooth, fleshy and reddish (on leaf, underside only).
- Stems - Stems can grow 3 to 7 feet tall (sometimes up to 10 feet), and several may emerge from one taproot. The smooth, fleshy, thick stems are typically reddish to deep red-purple, and are branched in the upper portion. Stems can attain a diameter of 4 inches and are usually hollow.
- Leaves - The large, alternately arranged leaves are smooth, fleshy and shiny. Leaves are elliptical to egg-shaped, tapering to a point at one end and into a long leaf stalk (1/3 to 2 inches long) at the other. Leaves range from 5 to 20 inches long, and are usually 1/3 as wide as they are long. The upper leaf surface is dark green, while the lower surface is pinkish-green with conspicuous pink veins. Leaves become smaller toward the top of the plant.
- Flowers - Whitish-green flowers are produced in long, narrow, unbranched, erect to nodding clusters (4 to 8 inches long) at the ends of stems and upper branches. Each flower in the cluster is borne on an individual flower stalk. Flowers are 1/4 inch wide and composed of 5 petal-like, rounded sepals (floral leaves; flowers lack true petals). The flower cluster often occurs opposite a leaf.
- Fruits & Seeds - Each flower develops into an 8- to 10-chambered, shiny, juicy berry (1/4 inch wide), with 1 seed per chamber. Berries are flattened, round in outline, and initially green, becoming black-purple at maturity. As the fruit ripens, the clusters become heavy and drooping, resembling a grape bunch, and the stems holding the berries turn a bright red-purple. Ripe berries are filled with crimson juice. Seeds are 1/8 inch wide, lens-shaped, black and shiny.
Biology: Common pokeweed seedlings emerge from mid-spring to early summer, and shoots emerge from previously established roots in the spring. Flowers are produced from July to September. Pokeweed seeds can remain viable in the soil for up to 40 years. Birds commonly eat pokeweed berries without adverse reactions and are probably an important means for distributing this species.
This poisonous weed is often found in pastures, fencerows and barnyards, in unfortunately close proximity to livestock, and is becoming an increasing problem in no-tillage crops. To control a few scattered plants, cutting below the root crown is effective (digging up the large taproot is very difficult). For larger infestations, growing a cultivated crop for 1 to 2 years will help reduce common pokeweed populations.
Toxicity: All parts of common pokeweed are toxic to humans, pets and livestock. Roots are the most poisonous, leaves and stems are intermediate in toxicity (toxicity increases with maturity), and berries are the least toxic. Since common pokeweed is not very palatable, most animals avoid eating it unless little else is available, or if it is in contaminated hay. Horses, sheep and cattle have been poisoned by eating fresh leaves or green fodder, and pigs have been poisoned by eating the roots. Children are most frequently poisoned by eating raw berries. Infants are especially sensitive and have died from eating only a few raw berries. Although boiled young shoots have been eaten as greens and berries cooked in pie, ingestion of any part of the plant cannot be recommended. Adults have been poisoned, sometimes fatally, by eating improperly prepared leaves and shoots, especially if part of the root is harvested with the shoot, and by mistaking the root for an edible tuber. Research with humans has also shown that common pokeweed can cause mutations (possibly leading to cancer) and birth defects. Since the juice of pokeweed can be absorbed through the skin, contact of plant parts with bare skin should be avoided.
Symptoms of poisoning from common pokeweed include a burning sensation in the mouth, salivation, gastrointestinal cramps, vomiting and bloody diarrhea. Most people and animals recover within 1 to 2 days if only small quantities are eaten. If large quantities are consumed, more severe symptoms can occur, such as anemia, altered heart rate and respiration, convulsions and death from respiratory failure. The primary toxic compounds are thought to be oxalic acid, saponins (phytolaccotoxin and phytolaccigenin) and an alkaloid (phytolaccin).
Facts and Folklore:
- The common name 'pokeweed' originates from the Native American word for 'blood', referring to the red dye that can be made from the fruit (however, the color is difficult to fix). Some of the other common names, such as 'inkberry' and 'inkweed', refer to this use.
- Juice from pokeweed berries was once used to 'improve' the color of cheap red wine.
- Supporters of President James Polk wore pokeweed twigs instead of campaign buttons during the 1845 campaign.
- Medical researchers have isolated a protein (pokeweed antiviral protein or PAP) from pokeweed that is being used to try to inhibit the replication of the HIV virus in human cells.
- Roots, leaves and berries of common pokeweed were used medicinally by Native Americans and early settlers to treat a variety of conditions from hemorrhoids to headaches.
- The young shoots and leaves of pokeweed have been eaten as greens ('poke sallet'), boiled with the water changed several times prior to consumption. The taste is described as similar to that of asparagus or spinach. Berries have been used to make pie. However, ingestion of any part of common pokeweed cannot be recommended.