Phytolacca americana

Phytolacca americana, also known as American pokeweed, pokeweed, poke sallet, dragonberries is a poisonous, herbaceous perennial plant in the pokeweed family Phytolaccaceae growing up to 8 ft (2.4m) in height. It has simple leaves on green to red or purplish stems and a large white taproot. The flowers are green to white, followed by purple to almost black berries which 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 animals (i.e., to species that are unaffected by its mammalian toxins).

Phytolacca americana
Scientific classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Order: Caryophyllales
Family: Phytolaccaceae
Genus: Phytolacca
Species:
P. americana
Binomial name
Phytolacca americana
Synonyms[1][2]
  • Phytolacca decandra L.
  • Phytolacca rigida Small

Pokeweed is native to eastern North America, the Midwest, and the Gulf Coast, with more scattered populations in the far West. It is also naturalized in parts of Europe and Asia. It is considered a pest species by farmers.[3] Pokeweed is poisonous to humans, dogs, and livestock. In early spring, shoots and leaves (not the root) are edible with proper cooking, but they later become deadly, 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.

General description
Pokeweed berries

Pokeweed is a member of the Phytolaccaceae family, and is a large native herbaceous perennial plant,[4] growing up to 2.5m (8 feet) in height over the course of a summer.[4] One to several branches grow from the crown of a thick, white, fleshy taproot, each a "stout, smooth, green to somewhat purplish stem;" with simple, entire leaves with long petioles alternately arranged along the stem.[4]

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 symmetric, white or green, with 4-5 sepals and no petals. The flowers develop in elongated clusters termed racemes.[4][5] The seeds have long viability, able to germinate after many years in the soil.

Birds are unaffected by the poisons in the berries (see below),[4] and eat them, dispersing the seeds. Seed are also found in commercial seed (e.g., vegetable seed packets).[4] 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.[6] Distribution via birds is thought to account for the appearance of isolated plants in areas otherwise free from pokeweed.[4]

Common Names

Phytolacca americana or pokeweed is also known as pokeberry,[4][7] poke root,[7] Virginia poke (or simply poke),[7][8] pigeonberry,[7][8] inkberry,[4] redweed or red ink plant.[8] When used in Chinese medicine, it is called chuíxù shānglù (垂序商陸).[7][9][10] As food, it is called poke sallet, or more commonly poke salad, sometimes spelled polk salad.

Toxicity, poisoning and mortality

All parts of the plant can be toxic and pose risks to human and mammalian health.[11][4][12][13][14] Toxins are found in highest concentration in the rootstock, then leaves and stems, then the ripe fruit.[11][12] The plant generally gets more toxic with maturity,[11] with the exception of the berries, which are dangerous even while green.[14]

Children may be attracted by clusters of berries.[4] Ohio Agricultural Research and Development Center (OARDC) note that[11]

Children are most frequently poisoned by eating raw berries. Infants are especially sensitive and have died from eating only a few raw berries. 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.

Pokeweed is to be avoided during pregnancy and children consuming even one berry may require emergency treatment.[15] The plant sap can cause dermatitis in sensitive people.[15]

Birds are apparently immune to this poison.[4] The plant is not palatable to animals and is avoided unless little else is available or it is present in contaminated hay, but horses, sheep and cattle have been poisoned by eating fresh leaves or green fodder and pigs have been poisoned by eating the roots.[11]

If death occurs, it is usually due to respiratory paralysis.[4]

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.[16]

Symptoms and response to poisoning

Owen states:[4]

If taken internally, pokeweed is a slow acting but a violent emetic. Vomiting usually starts about 2 hours after the plant or parts of it have been eaten. Severe cases of poisoning result in purging, spasms, and sometimes convulsions. If death occurs, it is usually due to paralysis of the respiratory organs. Cases of animal or human poisoning should be handled by a veterinarian or a physician.

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."[11] If only small quantities are ingested, people and animals recover within one to two days.[11][17]

Habitat and range

Pokeweed is native to eastern North America, the Midwest, the Gulf Coast, and the West Coast of the USA.[18] It is an introduced weed in Japan.

Morphology
A cluster of Pokeweed berries

Plant Type: Perennial herbaceous plant which can reach a height of 3m (10 feet) but is usually 1.2m (4 feet) to 2m (6 feet). 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. There is 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.

Leaves: The leaves are alternate with coarse texture with moderate porosity. Leaves can reach sixteen inches in length. Each leaf is entire. Leaves are medium green and smooth, with a distinct odor that many characterize as unpleasant.

Flowers: The flowers have 5 regular parts with upright stamens and are up to 0.2 inches (5 mm) 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.

Fruit: A shiny dark purple berry 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.

Root: Thick central taproot which grows deep and spreads horizontally. Rapid growth. Tan cortex, white pulp, moderate number of rootlets. Transversely cut root slices show concentric rings. No nitrogen fixation ability.[7][15]

Chemical components

Various sources discuss notable chemical constituents of the plant.[19] The entire pokeweed plant contains a poisonous substance similar to saponin and the "alkaloid phytolaccine also occurs in small amounts.[4] The Canadian Poisonous Plants Information System and Heller at the National Library of Medicine say that phytolaccagenin and the alkaloid phytolaccatoxin contribute to human poisoning.[12] [13] Toxic components include triterpene saponins based on the triterpene genins, phytolaccagenin, jaligonic acid, phytolaccagenic acid (phytolaccinic acid), esculentic acid, and pokeberrygenin,[20] and phytolaccasides A, B, D, E, and G, and phytolaccasaponins B, E, and G.[21][22]

Triterpene saponins isolated from the berries of pokeweed uncharacterized as to toxicity include esculentoside E; and phytolaccasides C and F, and oleanolic acid, and 3-oxo-30-carbomethoxy-23-norolean-12-en-28-oic acid.[20] Triterpene alcohols isolated include 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.[20]

Other than starch and various tannins, other small molecule natural products isolated from pokeweed include canthomicrol, astragalin, and caryophyllene.[20] Seeds contain the phenolic aldehyde caffeic aldehyde.[23] Proteins of interest include various lectins, protein PAP-R, and pokeweed mitogen (PWM), as well as a toxic glycoprotein.[13]

Uses

Horticultural and ecological utility

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), other bird species including mourning dove (Zenaida macroura), and cedar waxwing (Bombycilla cedrorum). Small mammals apparently tolerant of its toxins include raccoon, opossum, red and gray fox, and the white-footed mouse.[6][24]

Pokeweed is used as a sometime food source by the larvae of some Lepidoptera species, including the giant leopard moth (Hypercompe scribonia).[25]

Some pokeweeds are grown as ornamental plants, mainly for their attractive berries. A number of cultivars have been selected for larger fruit panicles.[26]

Folk and alternative medicine

Owen notes that "Indians and early settlers used the root in poultices and certain drugs for skin diseases and rheumatism."[4]

The late 19th century herbal, the King's American Dispensatory, describes various folk medical uses that led individuals to ingest pokeberry products.[27] Phytolacca extract was advertised as a prescription weight loss drug in the 1890s.[28]

Pokeweed is promoted in alternative medicine as a dietary supplement that can treat a wide range of maladies including mumps, arthritis and various skin conditions.[29] While pokeweed has been subject to laboratory research, there is no medical evidence that it has any beneficial effect on human health.[29]

Food uses
Woman preparing poke salad

Poke is a traditional southern Appalachian food. The leaves and stems of young plants can be eaten, but must be cooked by boiling two or more times with the water drained and replaced each time. The leaves taste similar to spinach; the stems, similar to asparagus. A typical recipe is to remove the leaves from the young plant, rinse them in cool water, bring the leaves to a rolling boil in a large pot for about 20 minutes, discard the cooking water, rinse them in cool water, repeat the boiling and the rinsing at least two more times, panfry the leaves in bacon grease for a two minutes, add bacon, and salt and pepper to taste.[30] What is essential is that the leaves be young and that they be boiled at least twice with the water fresh each time.

The root are never eaten and cannot be made edible, but a late 19th century herbal, the King's American Dispensatory, describes various folk medical uses that led individuals to ingest pokeberry products,[27] and festivals still celebrate the plant's use in its historical food preparations (see below).

As late as the 1990's two companies commercially canned and sold pokeweed, but in 2000 the last one, the Allen Canning Company of Siloam Springs, Arkansas, closed down its operation.[31]

Other uses

Plant toxins from Phytolacca are being explored as a means to control zebra mussels.[32][33]

The toxic extract of ripe pokeweed berries can be processed to yield a pink dye.[34][35][36]

During the middle of the 19th century wine often was coloured with juice from pokeberries.[37]

Nutrition
Pokeberry shoots, drained after cooking by boiling (without salt).
Nutritional value per 100 g (3.5 oz)
Energy84 kJ (20 kcal)
3.1 g
Sugars1.6 g
Dietary fiber1.5 g
0.4 g
2.3 g
VitaminsQuantity %DV†
Vitamin A equiv.
54%
435 μg
48%
5200 μg
1747 μg
Thiamine (B1)
6%
0.07 mg
Riboflavin (B2)
21%
0.25 mg
Niacin (B3)
7%
1.1 mg
Vitamin B6
9%
0.111 mg
Vitamin C
99%
82 mg
Vitamin K
103%
108 μg
MineralsQuantity %DV†
Calcium
5%
53 mg
Iron
9%
1.2 mg
Magnesium
4%
14 mg
Manganese
16%
0.336 mg
Phosphorus
5%
33 mg
Potassium
4%
184 mg
Sodium
1%
18 mg
Link to USDA Database entry
†Percentages are roughly approximated using US recommendations for adults.
Source: USDA Nutrient Database

As shows in the sidebar, a 100g serving of pokeweed contains 20 calories and 3.1 grams of carbohydrates, 1.6 grams of sugars, 1.5 grams of dietary fiber, 0.4 grams of fat, 2.3 grams of protein, and is a rich source of vitamin A, vitamin B2, vitamin C, vitamin K, and manganese. It contains low levels of vitamin B1, vitamin B6, iron, calcium, magnesium, phosphorus, and potassium.

Cultural significance

In music

A 1969 hit written and performed Tony Joe White, "Polk Salad Annie", is about poke sallet, the cooked greens-like dish made from pokeweed. The lyrics include:[38][39]

And in the fields looks somethin' like a turnip green
And everybody calls it polk salad, polk salad

Elvis Presley covered the song.

In local Southern festivals

Poke salad festivals are held annually in several small southern towns, though often these celebrations are only remotely related to the plant as food or medicine (see [40] and individual festival references below). Locations include:

In Oklahoma, poke salad may be added to the annual wild onion dinners.[45]

Berry clusters

References
  1. The Plant List: A Working List of All Plant Species, retrieved 15 August 2015
  2. Flora of China online, retrieved 15 August 2015
  3. Oneto, Scott (August 15, 2018). "Pokeweed: A giant of a weed!". Agriculture and Natural Resources, University of California.
  4. Michael D. K. Owen, 1988, "Pokeweed (Phytolacca americana L.)", Publication Pm-746 of the Iowa State University Extension Service, Ames, IA: Iowa State University, see , accessed 2 May 2015
  5. Each flower has 10 stamens and a 10-cell pistil and gives rise to a 10-celled berry
  6. 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.
  7. 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.
  8. 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, ISBN 978-0-02-505470-7, see , accessed 2 May 2015.
  9. Further unlisted names that appear in Hortus Third (Bailey, Bailey, et al., 1976, op. cit.) include: cancer jalap, oakum, garget, pocan, and scoke.
  10. 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.
  11. John Cardina, Cathy Herms, Tim Koch & Ted Webster, 2015, "Entry: Common Pokeweed, Phytolacca americana", in Ohio Perennial and Biennial Weed Guide, Wooster, OH: Ohio Agricultural Research and Development Center (OARDC), see OARDC Pokeweed, accessed 2 May 2015.
  12. Jacob L. Heller, 2103, "Pokeweed poisoning", at MedlinePlus (online), October 21, 2013, see , accessed 2 May 2015.
  13. CBIF CPPIS, 2013, "All Plants (Scientific Name): Phytolacca americana," at Canadian Biodiversity Information Facility, Species Bank, Canadian Poisonous Plants Information System, (online), June 5, 2013, see , accessed 2 May 2015.
  14. Amitava Dasgupta, 2011, Effects of Herbal Supplements on Clinical Laboratory Test Results, Volume 2, Patient Safety, Walter de Gruyter, ISBN 3110245620, see , accessed 2 May 2015.
  15. Anon., 2015, "Entry: Phytolacca americana - L.," at Plants For A Future (organizational webpage), see , accessed 2 May 2015.
  16. Lewis, W. H. & Smith, P. R.; Smith (December 1979). "Poke root herbal tea poisoning". J. Am. Med. Assoc. 242 (25): 2759–60. doi:10.1001/jama.242.25.2759. PMID 501875.CS1 maint: multiple names: authors list (link)
  17. One study performed in Oklahoma in 1962 concluded that the oral lethal dose of fresh poke berries 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 Ogzewalla, Mossberg, Beck, Farrington (1962). "Studies on the Toxicity of Poke Berries" (PDF). Proc. Of the Okla. Acad. Of Sci.: 54–57.CS1 maint: multiple names: authors list (link)
  18. "Plant Profile:Phytolacca americana L., American pokeweed". USDA Natural Resources Conservation Service PLANTS Database. Retrieved 16 November 2017.
  19. Bensky, Dan, Steven Clavey, Steven & Stoger, Erich, 2004, Chinese Herbal Medicine, Materia Medica, 3rd Ed., Eastland Press.
  20. Kang, S.S. & Woo, W.S. (1980). "Triterpenes from the berries of Phytolacca americana". J. Nat. Prod. 43 (4): 510–3. doi:10.1021/np50010a013.
  21. Suga, Y., Maruyama, Y., Kawanishi, S. & Shoji, J. (1978). "Studies on the constituents of phytolaccaceous plants. I. On the structures of phytolaccasaponin B, E and G from the roots of Phytolacca americana L". Chem. Pharm. Bull. 26 (2): 520–5. doi:10.1248/cpb.26.520.CS1 maint: multiple names: authors list (link)
  22. Tang, W. & Eisenbrand, G., 1992, Chinese Drugs of Plant Origin: Chemistry, Pharmacology, and Use in Traditional and Modern Medicine, New York, NY: Springer-Verlag, p. 765.
  23. 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.
  24. 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.
  25. 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 "Archived copy". Archived from the original on 2015-09-20. Retrieved 2015-05-03.CS1 maint: archived copy as title (link), accessed 2 May 2–15.
  26. "Phytolacca americana American pokeweed". Royal Horticultural Society. 2017. Retrieved 16 November 2017. White-pink flowers appear in racemes from mid-summer to early autumn, followed by crimson-black berries in autumn
  27. John King, Harvey Wickes Felter & John Uri Lloyd, 1898, "Entry: Phytolacca," in King's American Dispensatory, Cincinnati : Ohio Valley Co., see and , accessed 2 May 2015.
  28. The Medical and surgical reporter (69th, July-Dec 1893 ed.). Philadelphia, Pa.: Crissy & Markley, Printers. p. 1561.
  29. Ades TB, ed. (2009). Pokeweed. American Cancer Society Complete Guide to Complementary and Alternative Cancer Therapies (2nd ed.). American Cancer Society. pp. 466–469. ISBN 9780944235713.
  30. "How to Identify, Harvest and Prepare Pokeweed and Poke Sallet". Delishably.com. Retrieved December 14, 2018.
  31. "Pokeweed: Prime Potherb," Eat the Weeds, http://www.eattheweeds.com/can-be-deadly-but-oh-so-delicious-pokeweed-2/
  32. Harold H. Lee, Lemma Aklilu, and Harriett J. Bennett, 1992, The use of Endod (Phytolacca dodecandra) to Control the Zebra Mussels (Dreissena polymorpha), Chapter 37, pp. 643-656, in Zebra Mussels Biology, Impacts, and Control, Thomas F. Nalepa & Don W. Schloesser, Eds., Boca Raton, FL:CRC Press, ISBN 0873716965, see , accessed 5 May 2015.
  33. US application 5252330, Harold H. Lee; Peter C. Fraleigh & Lemma Aklilu, "Method of controlling zebra mussels with extract of Phytolacca dodecandra", published 1993-10-12, assigned to University of Toledo.
  34. Pesha Black & Micah Hahn, 2004, "Pokeweed, Phytolacca americana, Family: Phytolaccaceae," at [Guide to] Practical Plants of New England (student project pages), see "Archived copy". Archived from the original on 2015-02-17. Retrieved 2015-05-03.CS1 maint: archived copy as title (link), accessed 2 May 2015.
  35. Brooklyn Botanical Garden. "Weed of the Month: Pokeweed". www.bbg.org. Retrieved 23 September 2017.
  36. Tull, Delena (2013). Edible and useful plants of the Southwest : Texas, New Mexico, and Arizona : including recipes, teas and spices, natural dyes, medicinal uses, poisonous plants, fibers, basketry, and industrial uses (Revised ed.). University of Texas press. p. 257. ISBN 978-0-292-74827-9. Retrieved 23 September 2017.
  37. Nilsson et al. 1970. "Studies into the pigments in beetroot (Beta vulgaris L. ssp. vulgaris var. rubra L.)"
  38. Doppelbauer, Martin (2008). "Tony Joe White - His Music". Archived from the original on May 3, 2015. Retrieved May 2, 2015.
  39. White, Tony Joe (1969). "Polk Salad Annie [Lyrics]". New York, NY: Sony/ATV Music Publishing. Retrieved May 2, 2015.
  40. APSFA, 2015, "Schedule of Events," at The Annual Poke Salad Festival Association, Annual Poke Salad Festival, Blanchard, Louisiana, at "Archived copy". Archived from the original on 2015-03-25. Retrieved 2015-05-03.CS1 maint: archived copy as title (link), accessed 2 May 2015.
  41. "Poke Sallet Festival ['Browngrass will join them ... ']". The Jackson County Sentinel (Online ed.). April 28, 2015. p. 4. Archived from the original on 2015-05-05. Retrieved May 2, 2015.
  42. "Poke Sallet Festival Pageant". The Jackson County Sentinel (Online ed.). April 21, 2015. p. 3. Archived from the original on 2015-05-05. Retrieved May 2, 2015.
  43. "Poke Sallet Festival". Facebook Events. Gainesboro, Tennessee. Retrieved May 2, 2015. "This year will mark the 37th Annual Poke Sallet Festival "The Oldest Poke Sallet Festival in the state of Tennessee" Come and join us on Thursday May 7th, Friday May 8th and Saturday May 9th 2015 In Historical Downtown Gainesboro. Look for details that will be featured in a 16 page insert in the April 28 issue of the Jackson County Sentinel."
  44. "Harlan County Poke Sallet Festival - Home". Retrieved 5 April 2016.
  45. Milbauer, John A. "Wild Onion Dinners." Oklahoma History Center's Encyclopedia of Oklahoma History and Culture. (retrieved 2 March 2010)

Further reading and viewing
  • P.A.G.M. De Smet, 1993, "Phytolacca americana," in Adverse Effects of Herbal Drugs, Volume 2 (Peter A. G. M. Smet, Konstantin Keller, Rudolf Hänsel, & R. Frank Chandler, Eds.), Berlin:Springer Science & Business Media, ISBN 3642489060, see , accessed 2 May 2015.
  • ACS, 2008, "Entry: Pokeweed," at Find Support & Treatment; Treatments and Side Effects Complementary and Alternative Medicine; Herbs, Vitamins, and Minerals, see ACS Pokeweed entry, accessed 2 May 2015.
  • Tyler, V. E.; Brady, L. R. & Robbers, J. E., 1988, "Poisonous plants," in Pharmacognosy, 9th ed. Philadelphia:Lea and Febiger, Chapter 15, pp. 438–455.
  • Elvin-Lewis, Memory P. F.; Lewis, Walter Hepworth (2003). Medical Botany: Plants Affecting Human Health (2nd ed.). Chichester: John Wiley & Sons. p. 82ff. ISBN 978-0471628828.
  • "Tony Joe White - Polk Salad Annie," performance, date unknown, at , accessed 2 May 2015.
  • "Tony Joe White and Johnny Cash," performance, 1970, "Polk Salad (Poke Salit) Annie," from Johnny Cash Show, episode no. 27, April 8, 1970, at LiveLeak (online), see , accessed 2 May 2015.
  • Brennan Carley, 2014, "Foo Fighters Join Tony Joe White on Bluesy 'Polk Salad Annie' on 'Letterman'," Spin (online), October 16, 2014, see , accessed 2 May 2015.
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