Giant Hogweed or Cow Parsnip?

Media stories on giant hogweed have drawn attention to this invasive plant and the fact that it can cause skin irritation, blistering and burning upon contact. This has raised local public concerns and interest in the plant.

According to Alberta Agriculture and Forestry, all plants reported in Alberta to date have proven to be cow parsnip.

Cow Parsnip is:

  • a native plant, very common to Strathcona County
  • very similar to giant hogweed – both plants are members of the Carrot family (Apiaceae or Umbelliferae)
  • found in similar habitats as Giant Hogweed

There have been no confirmed giant hogweed plants identified in Strathcona County.

Physical differences

Giant Hogweed Cow Parsnip
  • 3 to 5 metres tall
  • stem is 3 to 10 centimetres in diameter
  • stem has many purple spots and stiff bristles
  • leaf can be up to 1 to 1.5 metres wide
  • umbel-shaped (rounded white flower clusters in which the individual flower stalks arise from about the same point) up to 1 metre across
  • compound, lobed leaves (single leaves with lobes that look like a hand and fingers), which are deeply incised
 
Giant Hogweed
Giant Hogweed Leaf
  • 1 to 2.5 metres tall
  • stem is 2.5 to 5 centimetres in diameter
  • stem has a few purple areas and deep ridges, with fuzzy hairs
  • leaf is 1 to 2 metres wide
  • umbel-shaped (rounded white flower clusters in which the individual flower stalks arise from about the same point) up to 20 to 30 centimetres across
  • palmate-shaped, compound leaves (looks similar to a maple leaf, or an open palm with fingers outstretched), divided into 3 segments
Cow Parsnip
Cow Parsnip Leaf

Further information:

County Connect

Ask it, report it or suggest it using County Connect

Related pages

Quick links:
Alberta Invasive Species Council

Last updated: Thursday, June 13, 2019
Page ID: 44347