Heracleum maximum

Heracleum maximum is toxic to cats, dogs and horses. The reported severity is mild. Also known as Common Cowparsnip and Tube Clematis.

dogs cats horses

Mild Moderate Severe Critical

If your animal ate this plant, call your veterinarian now, or one of these services.

What do I do right now?
  • Australia
    Animal Poisons Helpline 1300 869 738 24 hours, every day · From $75
  • Austria
    Vergiftungsinformationszentrale 01 406 43 43 24 hours, every day
  • Belgium
    Centre Antipoisons 070 245 245 08:00 to 22:00 on weekdays, 10:00 to 22:00 at weekends · Human calls come first. The centre has no funding for animal work.
  • Canada
    Pet Poison Helpline (855) 764-7661 24 hours, every day · $89 for each incident
  • France
    Centre National d'Informations Toxicologiques Vétérinaires 04 78 87 10 40 08:30 to midnight, every day
  • Germany
    Giftinformationszentrum Bonn 0228 19240 24 hours, every day · Germany has no dedicated animal service. Human calls come first, so an animal call can wait.
  • Ireland

    Ireland has no animal poison service for owners. Call your veterinarian. An Irish veterinarian can consult the Veterinary Poisons Information Service in the United Kingdom.

  • Italy
    Centro Antiveleni di Milano 02 6610 1029 24 hours, every day
  • Netherlands
    Nationaal Vergiftigingen Informatie Centrum 088 755 8000 Veterinarians only 24 hours, every day · Call your veterinarian. Your veterinarian calls this line.
  • New Zealand
    Animal Poisons Helpline 0800 869 738 24 hours, every day
  • Sweden

    Giftinformationscentralen stopped answering questions about animals on 1 July 2018. Call your veterinarian or an animal hospital.

  • Switzerland
    Tox Info Suisse 145 24 hours, every day · From outside Switzerland, call +41 44 251 51 51.
  • United Kingdom
    Animal PoisonLine 01202 509 000 24 hours, every day · £35 from 08:00 to 20:00 Monday to Friday, £45 at other times
    Veterinary Poisons Information Service 020 7305 5055 Veterinarians only 24 hours, every day · A members only service. Your veterinarian calls this line.
  • United States
    ASPCA Animal Poison Control Center (888) 426-4435 24 hours, every day · A consultation fee applies
    Pet Poison Helpline (855) 764-7661 24 hours, every day · $89 for each incident

Symptoms to watch for

Dermatitis Photosensitivity

The color of each symptom follows the severity scale above.

About

Heracleum maximum, commonly known as cow parsnip, is the only member of the genus Heracleum native to North America. It is also known as American cow-parsnip, Satan celery, Indian celery, Indian rhubarb, poison turnip or pushki.

How this plant poisons

The plant contains furanocoumarins such as xanthotoxin, angelicin, pimpinellin and isopimpinellin, isoimperatorin, bergapten and isobergapten, 6‐isopentenyloxyisobergapten, and sphondin. In one study, the young leaves did not contain xanthotoxin, but older, senescing leaves contained "substantial amounts". Some of these furanocoumarins found in cow parsnip are known to have antimicrobial properties and are responsible for a rash producing erythematous vesicles (burn-like blisters) and hyperpigmentation that occurs after getting the clear sap onto one's skin. They are photosensitive, with the rash occurring only after exposure to ultraviolet light. Because of this, phytophotodermatitis causing skin blistering may occur after coming into contact with the sap on a sunny day. The scars and pigmentation from these blisters caused by some Heracleum species can last for months or years.

Common Names

  • Common Cowparsnip
  • Tube Clematis

Also recorded as American cow-parsnip, American hogweed, Cow Parsnip, Indian celery, Pushki and masterwort.

Facts

Family
Apiaceae
Duration
Perennial
Growth habit
Forb/herb
Native to
Labrador, Newfoundland, Alberta, British Columbia, Manitoba, New Brunswick, Nova Scotia, Northwest Territories
In the wild
US, CA, RU, JP, CN, KP + more
Source
Wikipedia, CC BY-SA 4.0

Countries with the most wild observations, from GBIF data.