Heracleum (plant) explained

Heracleum is a genus of biennial and perennial herbs in the carrot family Apiaceae. They are found throughout the temperate northern hemisphere and in high mountains as far south as Ethiopia. Common names for the genus or its species include hogweed^[1] and cow parsnip.^{[2] [3]}

The genus name Heracleum was described by Carl Linnaeus in 1753. It derives from the Ancient Greek "of Heracles", referring to the mythological hero.

Species

Many species of the genus Heracleum are similar in appearance.^[4] An outlier is H. mantegazzianum, the large size of which is exceptional. Common species include:

• Heracleum mantegazzianum, giant hogweed, native to the western Caucasus region of Eurasia, a serious invasive species in many areas of Europe and North America
• Heracleum sosnowskyi, Sosnowsky's hogweed, native to the eastern Caucasus, a common weed throughout Europe and Asia
• Heracleum persicum, Persian hogweed, native to Iran, Iraq, and Turkey
• Heracleum sphondylium, common hogweed, native to Europe and Asia
• Heracleum maximum, cow parsnip, native and common in North America

, Plants of the World Online accepts the following 88 species:,^[5] it had previously in 2019, up to 148.

Classification and naming

Other than size, the related species H. mantegazzianum, H. sosnowskyi, and H. persicum have very similar characteristics. The common name giant hogweed usually refers to H. mantegazzianum alone but in some locales that common name refers to all three species as a group.^[6] Both H. maximum and H. sphondylium are often referred to as cow parsnip. To avoid confusion, these species are sometimes referred to as American cow parsnip and European cow parsnip, respectively.^{[7] [8]}

The morphological similarity of species within the genus Heracleum and the difficulty of botanical identification has led to numerous synonyms and naming issues. For example, the classification of the species now widely known as H. maximum has been inconsistent. In the literature, the scientific names H. lanatum, H. maximum, and others are used interchangeably. Prior to 2000, the former name was most popular, but today the latter name is in vogue.

Phototoxic effects

Most species of the genus Heracleum are known to cause phytophotodermatitis.^[9] In particular, the public health risks of giant hogweed (H. mantegazzianum) are well known.^{[10] [11] [12]}

At least 36 species of the genus Heracleum have been reported to contain furanocoumarin,^[13] a chemical compound that sensitizes human skin to sunlight. Of those, at least 25 species contained a psoralen derivative, either bergapten (5-methoxypsoralen) or methoxsalen (8-methoxypsoralen). Three of those species (H. mantegazzianum, H. sosnowskyi, and H. sphondylium) were found to contain both psoralen derivatives.

Bibliography

• Logacheva . Maria . Valiejo-Roman . C. M. . Pimenov . Michael . ITS phylogeny of West Asian Heracleum species and related taxa of Umbelliferae–Tordylieae, with notes on evolution of their psbA-trnH sequences . Plant Systematics and Evolution . February 2007 . 270 . 3 . 139–157 . 10.1007/s00606-007-0619-x.

Notes and References

1. http://oxforddictionaries.com/definition/english/hogweed?q=hogweed hogweed
2. Book: Bailey, L.H. . Bailey, E.Z. . the staff of the Liberty Hyde Bailey Hortorium . 1976 . Hortus third: A concise dictionary of plants cultivated in the United States and Canada . Macmillan . New York . 978-0-02-505470-7 . registration .
3. Web site: Heracleum L. . Tropicos.org . Missouri Botanical Garden . 11 Oct 2011.
4. Web site: Giant Hogweed (Heracleum mantegazzianum): Best Management Practices in Ontario . MacDonald . Francine . Anderson . Hayley . May 2012 . Ontario Invasive Plant Council, Peterborough, ON . September 1, 2018.
5. Web site: Heracleum L. Plants of the World Online Kew Science . Plants of the World Online . 11 January 2022 . en.
6. Book: 87-7903-209-5 . The giant hogweed best practice manual: guidelines for the management and control of invasive weeds in Europe . Booy . Olaf . Cock . Matthew . Eckstein . Lutz . Hansen . Steen Ole . Hattendorf . Jan . Hüls . Jörg . Jahodová . Sárka . Krinke . Lucás . Marovoková . Lanka . Müllerová . Jana . Nentwig . Wolfgang . Nielsen . Charlotte . Otte . Annette . Pergl . Jan . Perglová . Irena . Priekule . Ilze . Pusek . Petr . Ravn . Hans Peter . Thiele . Jan . Trybush . Sviatlana . Wittenberg . Rüdiger . 2005 . Hørsholm: Center for Skov, Landskab og Planlægning/Københavns Universitet . September 1, 2018.
7. Web site: Heracleum sphondylium common names . EOL . September 15, 2018 .
8. Web site: German-English Dictionary: cow parsnip . dict.cc . September 15, 2018 .
9. The Electronic Textbook of Dermatology . Botanical Dermatology . McGovern . Thomas W . Barkley . Theodore M . 1998 . 37 . 5 . Section Phytophotodermatitis . Internet Dermatology Society . 10.1046/j.1365-4362.1998.00385.x . 9620476 . 221810453 . August 11, 2018.
10. Web site: Giant Hogweed Warning: Plant That Can Cause Blindness, Burn Skin, Spreads Into New State . Gander . Kashmira . June 18, 2018 . Newsweek . August 11, 2018.
11. Giant Hogweed And Photodermatitis . 10.31482/mmsl.2017.021 . 0372-7025 . Military Medical Science Letters. 2017 . 86 . 3 . 135–138 . Patocka . Jiri . Cupalova . Klara . free .
12. Phytophotodermatitis from Heracleum mantegazzianum . Contact Dermatitis . 1976 . 2 . 2 . 68–72 . Camm . E . Buck . HW . Mitchell . JC . 10.1111/j.1600-0536.1976.tb02987.x. 1017181 . 70428677 .
13. Book: Mitchell . John . Rook . Arthur . Botanical Dermatology: Plants and Plant Products Injurious to the Skin . 1979 . Greengrass . Vancouver . 692–699.