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 Rural Development, 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
  • 4.5 to 6 metres tall
  • stem is 2.5 to 7.5 centimetres in diameter
  • stem has many purple spots and stiff bristles
  • leaf can be up 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 0.75 metres across
  • compound, lobed leaves (single leaves with lobes that look like a hand and fingers), which are deeply incised
 
Giant Hogweed
Giant Hogweed Leaf
  • 1.5 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 0.5 to 1 metre wide
  • umbel-shaped (rounded white flower clusters in which the individual flower stalks arise from about the same point) up to 0.3 metre 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

Resources:

Further information:

Transportation and Agriculture Services
Phone: 780-417-7100
Email: transportationandagriculture@strathcona.ca

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Last updated: Thursday, May 23, 2019
Page ID: 44347