Veratrum

Veratrum
Veratrum album[1]
Scientific classification
Kingdom: Plantae
Clade: Angiosperms
Clade: Monocots
Order: Liliales
Family: Melanthiaceae
Tribe: Melanthieae
Genus: Veratrum
L. 1753
Synonyms[2]
  • Melanthium J.Clayton ex L.
  • Helleborus Gueldenst. 1791, illegitimate homonym not L. 1753 (Ranunculaceae)
  • Leimanthium Willd.
  • Anepsa Raf.
  • Evonyxis Raf.
  • Acelidanthus Trautv. & C.A.Mey.

Veratrum is a genus of flowering plants in the family Melanthiaceae.[3] It occurs in damp habitats across much of temperate and subarctic Europe, Asia, and North America.[2][4][5][6][7]

Veratrum species are vigorous herbaceous perennials with highly poisonous black rhizomes, and panicles of white or brown flowers on erect stems.[8] In English they are known as both false hellebores and corn lilies. Veratrum is not closely related to hellebores, nor do they resemble them.

Ecology

Veratrum species are used as food plants by the larvae of some Lepidoptera species including Setaceous Hebrew Character.

Habitat

Widely distributed in montane habitats of temperate Northern Hemisphere, Veratrum species prefer full sunlight and deep, wet soils, and are common in wet mountain meadows, swamps, and near streambanks.

Toxicity

Veratrum species contain highly toxic steroidal alkaloids (e.g. veratridine) that activate sodium ion channels and cause rapid cardiac failure and death if ingested.[9] All parts of the plant are poisonous, with the root and rhizomes being the most poisonous.[9] Symptoms typically occur between thirty minutes and four hours after ingestion and include nausea and vomiting, abdominal pain, numbness, headache, sweating, muscle weakness, bradycardia, hypotension, cardiac arrhythmia, and seizures.[9] Treatment for poisoning includes gastrointestinal decontamination with activated charcoal followed by supportive care including antiemetics for persistent nausea and vomiting, along with atropine for treatment of bradycardia and fluid replacement and vasopressors for the treatment of hypotension.[9]

The toxins are only produced during active growth. In the winter months, the plant degrades and metabolizes most of its toxic alkaloids. Native Americans harvested the roots for medicinal purposes during this dormant period.

Uses

Native Americans used the juice pressed from the roots of this plant to poison arrows before combat. The dried powdered root of this plant was also used as an insecticide.[10] Western American Indian tribes have a long history of using this plant medicinally, and combined minute amounts of the winter-harvested root of this plant with Salvia dorii to potentiate its effects and reduce the toxicity of the herb. The plants' teratogenic properties and ability to induce severe birth defects were well known to Native Americans.[10]

Medical research

During the 1930s Veratrum extracts were investigated in the treatment of high blood pressure in humans. Patients treated often suffered side effects due to the narrow therapeutic index of these products. Due to their toxicity and the availability of other less toxic drugs, use of Veratrum as a treatment for high blood pressure in humans was discontinued.[9]

Herbal medicine

Members of Veratrum are known both in western herbalism and traditional Chinese medicine as toxic herbs to be used with great caution. It is one of the medicinals ("Li lu") cited in Chinese herbal texts as incompatible with many other common herbs because of its potentiating effects. Especially, many root (and root-shaped) herbs, particularly ginseng, san qi, and hai seng, will create and or exacerbate a toxic effect.[11]

The roots of V. nigrum and V. schindleri have been used in Chinese herbalism, where plants of this genus are known as "li lu" (藜蘆). Li lu is used internally as a powerful emetic of last resort, and topically to kill external parasites, treat tinea and scabies, and stop itching.[11] Some herbalists refuse to prescribe li lu internally, citing the extreme difficulty in preparing a safe and effective dosage, and that death has occurred at a dosage of 0.6 gram.[11]

Species

Accepted species[2]

References

  1. ↑ 1897 illustration from Franz Eugen Köhler, Köhler's Medizinal-Pflanzen
  2. 1 2 3 Kew World Checklist of Selected Plant Families
  3. ↑ Tropicos, Veratrum L.
  4. ↑ Flora of North America, Vol. 26 Page 72, False hellebore, skunk-cabbage, corn-lily, vérâtre, varaire, Veratrum Linnaeus, Sp. Pl. 2: 1044. 1753; Gen. Pl. ed. 5: 468. 1754.
  5. ↑ Flora of China Vol. 24 Page 82 藜芦属 li lu shu Veratrum Linnaeus, Sp. Pl. 2: 1044. 1753.
  6. ↑ Altervista Flora Italiana, genere Veratrum includes photos and European distribution maps
  7. ↑ Biota of North America Program 2013 county distribution maps
  8. ↑ RHS A–Z encyclopedia of garden plants. United Kingdom: Dorling Kindersley. 2008. p. 1136. ISBN 1405332964.
  9. 1 2 3 4 5 Schep LJ, Schmierer DM, Fountain JS (2006). "Veratrum poisoning". Toxicol Rev. 25 (2): 73–8. PMID 16958554. doi:10.2165/00139709-200625020-00001.
  10. 1 2 Edible and Medicinal plants of the West, Gregory L. Tilford, ISBN 0-87842-359-1
  11. 1 2 3 Bensky, D., Clavey, S., Stoger, E. (2004). Materia Medica (3rd edition). Seattle: Eastland Press. p. 461.
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