Giant Hogweed
- Information from Wikipedia on this tall plant, Heracleum mantegazzianum, and its toxicity.
- http://en.wikipedia.org/wiki/Giant_Hogweed

Heracleum sphondylium
- Several photographs of Hogweed and the identifying features of the plant.
- http://www.plant-identification.co.uk/skye/umbelliferae/heracleum-sphondylium.htm

Giant Hogweed (Heracleum mantegazzianum)
- Description and images of this invasive weed.
- http://www.ecy.wa.gov/programs/wq/plants/weeds/aqua012.html

Invasive Species: Hogweed Profile
- Extensive list of links to weed fact sheets about Heracleum mantegazzianum.
- http://www.invasivespecies.gov/profiles/hogweed.shtml