Below are two links to information about Giant Hogweed. © 2020. The plant has moved into Ontario and British Columbia at this time and recent media stories have raised local public concerns and interest in the plant. Giant hogweed (H. mantegazzianum) is native to the Caucasus but is considered an invasive species in many areas outside its native range. Hollow, ridged stems vary from 3–8 cm (1–3 in) in diameter, occasionally up to 10 cm (4 in) in diameter and ca… It is a garden ornamental from southwest Asia that is naturalizing in North America and becoming more common in southern and central Ontario. Additional Information & Resource Library. The sap from all parts of the Giant Hogweed causes a phytophotodermatitis affect  when the sap gets onto your skin. Stems have prominent purple blister-like pustules on the stems. In summer, Giant Hogweed can reach a height of 5 metres. Giant hogweed is also much larger than cow parsnip - it can grow to be several metres tall. It does not reproduce by vegetative means, e.g. Giant Hogweed was originally introduced to North America as an ornamental plant; however in some parts of North America thi­s plant has escaped cultivation. Giant hogweed can be a health hazard to humans and animals What does giant hogweed look like? Because of the significant Human Health Risk researchers should be aware of this plant and how to recognize it. It invades old fields and native habitats such as open woodlands. It is highly recommended to review the information on the giant hogweed to confirm a positive sighting in Calgary. A mature plant has huge leaves, between 1–1.5 m (3 ft 3 in–4 ft 11 in) wide, and a stout, bright green stem with extensive dark reddish-purple splotches and prominent coarse white hairs, especially at the base of the leafstalk. Giant hogweed looks extremely similar to another plant species found in Calgary - cow parsnip. Driving University of Alberta vehicles. Leaf stalks are spotted and produce a compound leaf that can expand to 1.5 met ers across. Wild parsnip is often confused with similar-looking giant hogweed, cow parsnip, Queen Anne’s lace and angelica. It is an invasive, alien plant that originates from the Caucasus Mountains in west central Asia where it grows in subalpine meadows and forest edges. What is giant hogweed? Virginia Tech researchers who helped identify the dangerous Giant Hogweed plants in Clarke County, Virginia, want residents to stay on the lookout for the plant with toxic sap that can cause severe burns — but also stressed that the weeds are believed to have been planted intentionally decades ago and haven’t spread in the years since. Giant Hogweed was introduced to the UK in the early 19th Century. Seed bank and dispersal After falling from the parent plant, the seeds accumulate and mature in the soil. The Giant Hogweed plant is found in many provinces and in many States. Giant Hogweed (Heracleum mantegazzianum) is a perennial plant and a member of the carrot family. ~ Giant hogweed is a good competitor as its leaves grow early in the season and it shades out lower growing species. Positive sightings can be reported to 311 or 403-268-CITY (2489) if calling from outside Calgary.​​​, Learn more about common pests in Calgary​. Risk Management and Hazard Assessment, 08. Workplace BC:   Toxic Plant, If you should come into contact with the sap from a Giant Hogweed plant, below is a link with information regarding the medical treatment. The lower leaves are often 1m more in size and distinctively spiky. Giant hogweed (Heracleum mantegazzianum), is a tall, cow parsley -like plant with thick bristly stems that are often purple-blotched. Large flower (up to 75 cm wide) with 50 or more flower stems or rays. According to Alberta Agriculture and Forestry, all plants reported in Alberta to date have proven to be cow parsnip. It's called giant hogweed and it doesn't play nice with humans. It was used as an ornamental garden plant and its seeds were used in cooking. Giant hogweed, Heracleum mantegazzianum, which has been featured recently in national media reports, is one of the new invasive alien plants designated as Prohibited Noxious under Alberta’s newly revised Weed Control Act. These blisters can form black or purplish scars that can last for several years. Giant Hogweed is a dangerous. The leaves are incised and deeply lobed. Do not touch any plant suspected to be giant hogweed, as contact with it can cause burning of the skin, as well as other complications. The Giant Hogweed plant has also been relocated to many other countries so researchers can expect to find this plant worldwide. Under ideal conditions, a plant can reach a height of 5.5 m (18 ft 1 in). Giant Hogweed First Aid treatment. Giant hogweed can grow to more than 4 metres tall, with flower umbels that can reach 2 feet in diameter. Visit the Oregon Department of Agriculture's Giant Hogweed Identification site for more information on the differences in giant hogweed and cow parsnip. Description Grows up to 6 meters or more. Link to Youtube, Giant Hogweed Identification and Comparison with Cow Parsnip The main difference is the height and the fact that it can cause serious burns to the skin. Walkers who may brush against it, or gardeners who may unwittingly strim the plant getting the sap on themselves. Giant hogweed is often confused with cow parsnip (Heracleum lanatum), a very common native in Alberta. Giant hogweed (Heracleum mantegazzianum) is a plant in the Apiaceae family (previously known as the Umbelliferae). It is an invasive, alien plant that originates from the Caucasus Mountains in west central Asia where it grows in subalpine meadows and forest edges.