Phytolacca americana, also known as American pokeweed, pokeweed, polk salad, poke sallet, pokeberry, dragonberries, pigeonberry weed, and inkberry, is a poisonous, herbaceous, perennial plant in the pokeweed family Phytolaccaceae. This pokeweed grows . It has simple leaves on green to red or purplish stems and a large, white taproot. The flowers are green to white, followed by berries, which ripen through red to purple to almost black and are a food source for songbirds such as gray catbird, northern mockingbird, northern cardinal, and brown thrasher, as well as other birds and some small nonavian animals (i.e., for species that are unaffected by its mammalian toxins).
Pokeweed is native to eastern North America, the Midwest, and the South, with more scattered populations in the Far West, where it was introduced. It is also naturalized in parts of Europe and Asia. It is considered a pest species by farmers. Pokeweed is poisonous to humans, dogs, and livestock. In spring and early summer, shoots and leaves (not the root) are edible with proper cooking (hence the common name "poke sallet"), but later in the summer, they become poisonous, and the berries are also poisonous. It is used as an ornamental in horticulture, and it provokes interest for the variety of its natural products (toxins and other classes), for its ecological role, its historical role in traditional medicine, and for some utility in biomedical research (e.g., in studies of pokeweed mitogen). In the wild, it is easily found growing in pastures, recently cleared areas and woodland openings, edge habitats such as along fencerows, and in wastelands.
Description
Pokeweed is a member of the family Phytolaccaceae, and is a large herbaceous perennial plant, growing up to in height over the course of a summer. One to several branches grow from the crown of a thick, white, fleshy taproot; Michael D. K. Owen describes the branches as "stout, smooth, [and] green to somewhat purplish". Simple, entire leaves with long petioles are alternately arranged along the stem.
Pokeweeds reproduce only by their large, glossy black, lens-shaped seeds, which are contained in a fleshy, 10-celled, purple-to-near-black berry that has crimson juice. The flowers are perfect, radially symmetrical, white or green, with four or five sepals and no petals. The flowers develop in elongated clusters termed racemes.Each flower has 10 stamens and a 10-cell pistil and gives rise to a 10-celled berry The seeds have long viability, able to germinate after many years in the soil.
Morphology
Plant Type: Perennial herbaceous plant which can reach a height of but is usually . The plant must be a few years old before the root grows large enough to support this size. The stem is usually red late in the season. The plant has an upright, erect central stem early in the season, which changes to a spreading, horizontal form later with the weight of the berries. The plant dies back to the roots each winter. The stem has a chambered pith.
The leaves are alternate with coarse texture with moderate porosity. Leaves can reach in length. Each leaf is entire and are medium green and smooth, with a distinct odor that many characterize as unpleasant.
The flowers have five regular parts with upright stamens and are up to wide. They have white, petal-like sepals without true petals, on white pedicels and peduncles in an upright or drooping raceme, which darken as the plant fruits. Blooms first appear in early summer and continue into early fall.
A shiny, dark purple berry is held in racemose clusters on pink pedicels with a pink peduncle. Pedicels without berries have a distinctive, rounded, five-part calyx. Fruits are round with a flat, indented top and bottom. Immature berries are green, turning white and then blackish purple.
Thick central taproot grows deep and spreads horizontally. Its growth is rapid, with a tan cortex, white pulp, and a moderate number of rootlets. Transversely cut root slices show concentric rings. The plant has no nitrogen-fixation ability.Anon., 2015, "Entry: Phytolacca americana – L.," at Plants For A Future (organizational webpage), see , accessed 2 May 2015.
Chemistry
The entire pokeweed plant contains triterpenes such as phytolaccagenin, jaligonic acid, phytolaccagenic acid (phytolaccinic acid), , and (in the berries), as well as the saponins phytolaccasides A, B, D, E, and G, and phytolaccasaponins B, E, and G (in the roots).
The roots also contain other triterpenoids such as oleanolic acid, α-spinasterol and its glucoside, α-spinasteryl-β-D-glucoside, and a palmityl-derivative, 6-palmytityl-α-spinasteryl-6-D-glucoside, as well as a similarly functionalized stigmasterol derivative, 6-palmityl-Δ7-stigmasterol-Δ-D-glucoside. Pokeweed berries also contain betalain pigments such as betanin and others. The leaves contain a number of common flavonols. Seeds of pokeweed contain the phenolic aldehyde caffeic aldehyde.Woo, W.S., Kang, S.S., 1979. A new phenolic aldehyde from the seeds of phytolacca americana. Soul Taehakkyo Saengyak Yonguso Opjukjip 18, 30–31.
Pokeweed also contains lectins, such as pokeweed mitogen.
Etymology The generic name, Phytolacca, comes from the Greek words ('plant') and —the scarlet dye secreted by the Kerria lacca scale insect. The specific name americana denotes this plant as native to America. The common name "poke" is derived from puccoon, pocan, or poughkone (from an Algonquin name for the plant). Its berries were once used to make ink, hence its other sometimes-used common name, inkberry.
Common names Phytolacca americana or pokeweed is also known as pokeberry,USDA-ARS, 2015, "Taxon: Phytolacca americana L.," at National Genetic Resources Program.Germplasm Resources Information Network – (GRIN) [Online Database], National Germplasm Resources Laboratory, Beltsville, Maryland, see , accessed 2 May 2015. poke root, Virginia poke (or simply poke),Bailey, L.H., Bailey, E.Z., and the staff of the Liberty Hyde Bailey Hortorium, 1976, Hortus third: A concise dictionary of plants cultivated in the United States and Canada, New York, NY:Macmillan, , see , accessed 2 May 2015. pigeonberry, inkberry, redweed, or red ink plant.Further unlisted names that appear in Hortus Third (Bailey, Bailey, et al., 1976, op. cit.) include: cancer jalap, oakum, garget, pocan, and scoke.Further unlisted names that appear at WebMD include American nightshade, American spinach, Baie de Phytolaque d'Amérique, Bear's Grape, Branching Phytolacca, Cancer Jalap, Chongras, Coakum, Coakum-Chorngras, Cokan, Crowberry, Épinard de Cayenne, Épinard des Indes, Faux Vin, Fitolaca, Garget, Herbe à la Laque, Hierba Carmin, Jalap, Kermesbeere, Laque, Phytolacca Berry, Phytolacca americana, Phytolacca decandra, Phytolaque Américaine, Phytolaque à Baies, Phytolaque Commun, Phytolaque d'Amérique, Pocan, Raisin d'Amérique, Red Plant, Scoke, Skoke, Teinturier, Teinturière, Vigne de Judée. See WebMD, 2015, "Pokeweed," at WebMD: Vitamin and Supplement (online), , accessed 2 May 2015. When used in Chinese medicine, it is called chuíxù shānglù ().Further unlisted names include: 垂序商陸（全國中草藥彙編），洋商陸（中國植物圖鑑），美國商陸（華北經濟植物誌要），美洲商陸（經濟植物手冊），美商陸（杭州藥用植物誌），洋商陸(臺灣)、花商陸、野胭脂(杭州)、白雞腿(江西/Vertical Shang Lu (National Compendium of Chinese Herbal Medicine), Foreign Shang Lu (Chinese Botanical Atlas), American Shang Lu (North China Economic Plant Journal), American Shang Lu (Economic Plant Manual), American Shang Lu (Hangzhou Medicinal Plant Journal), Foreign Shang Lu (Taiwan), Florist Lu, Wild Rouge (Hangzhou), White Chicken Leg (Jiangxi)
As food, it is called poke sallet, or more commonly poke salad, sometimes spelled polk salad, as used in Tony Joe White's 1968 song "Polk Salad Annie":
Distribution and habitat Pokeweed is native to eastern North America, the Midwest, the Gulf Coast, and the West Coast of the US. It is an introduced weed in Japan.
Ecology Birds are unaffected by the poisons in the berries and eat them, dispersing the seeds. The berries are reported to be a good food source for songbirds and other bird species and small animals that are unaffected by its toxins.Nancy L. Matthews, 1987, "Appendix F: Hab itat Assessment Manual," in Report: Anne Arundel Co., Offc. Planning and Zoning, Environmental and Special Projects Div., to Office of Coastal Resources Management, NOAA and State of Maryland Chesapeake Bay Critical Area Commission, August 1987, 9 pages, passim see , accessed 2 May 2015. Distribution via birds is thought to account for the appearance of isolated plants in areas otherwise free from pokeweed.
Pokeweed berries are reported to be a good food source for songbirds such as gray catbird (Dumetella carolinensis), northern mockingbird (Mimus polyglottos), northern cardinal (Cardinalis cardinals), brown thrasher (Toxostoma rufum), mourning dove (Zenaida macroura), and cedar waxwing (Bombycilla cedrorum). Small mammals apparently tolerant of its toxins include raccoon, opossum, red and gray foxes, and the white-footed mouse.Other birds reported to include pokeweed in their diets include bluebirds, crested flycatchers, fish crows, hairy woodpeckers, kingbirds, phoebes, robins, starlings, and yellaw-breasted chats, see Matthews, 1987, op. cit.
Pokeweed is sometimes used as a food source by black bears.
Pokeweed also is used as a sometime food source by the larvae of some Lepidoptera species, including the giant leopard moth (Hypercompe scribonia).Donald W. Hall, 2015, "Giant woolly bear (larva), giant or great leopard moth (adult) [scientific name: Hypercompe scribonia (Stoll 1790) (Lepidoptera: Erebidae: Arctiinae)]," at Institute of Food and Agricultural Sciences: Featured creatures, Gainesville, FL:Florida Department of Agriculture and Consumer Services, Division of Plant Industry, Table 1, see , accessed 2 May 2–15.
Toxicity All parts of the plant can be toxic and pose risks to the health of all mammals, including humans. Toxins are found in highest concentration in the rootstock, then leaves and stems, then the ripe fruit. The plant generally gets more toxic with maturity, with the exception of the berries, which are dangerous even while green.
Children may be attracted by clusters of berries. Ohio Agricultural Research and Development Center (OARDC) notes:
Pokeweed is to be avoided during pregnancy, and children consuming even one berry may require emergency treatment. The plant sap can cause dermatitis in sensitive people.
Most mammals dislike the taste of the plant and avoid it unless it is the only food source or if it is mixed in their feed. The fresh leaves have poisoned livestock that have eaten the green leaves or roots. If death occurs, it is usually due to respiratory paralysis.
Pokeweed poisoning was common in eastern North America during the 19th century, especially from the use of tinctures as antirheumatic preparations and from ingestion of berries and roots that were mistaken for parsnip, Jerusalem artichoke, or horseradish.
Symptoms and response to poisoning Owen states:
The OARDC staff scientists note that symptoms of poisoning include "a burning sensation in the mouth, salivation, gastrointestinal cramps, and vomiting and bloody diarrhea", and that depending upon the amount consumed, more severe symptoms can occur, including "anemia, altered heart rate and respiration, convulsions, and death from respiratory failure." If only small quantities are ingested, people and other mammals recover within one to two days.One study performed in Oklahoma in 1962 concluded that the oral lethal dose of fresh pokeberries in mice was about 300 gm/kg body weight and for dry berries was about 100 gm/kg body weight, and that liquid berry extract was 80 times as toxic when injected intraperitoneally as when taken orally. See
Uses
Horticulture
Some pokeweeds are grown as ornamental plants, mainly for their attractive berries. A number of cultivars have been selected for larger fruit panicles.
Folk and alternative medicine