Heracleum mantegazzianum

Species category

Weed

Common name

giant hogweed

Diagnostic characters

Planting unit

MericarpMericarp:
One-half of a two-sectioned fruit known as a schizocarp (e.g. carrot).

Shape

OvalOval:
Broadly elliptic.

Size

  • Length 8–10 mm 
  • Width 5–7 mm 
  • Thickness 1–1.2 mm 

Color

White with brown longitudinal lines

Texture

Smooth 

Other structures

Scar on apicalApical:
The distal end of the fruit or seed away from the point of attachment or attachment scar.
end. Margin winged.

Identification notes

Longitudinal brown lines are bulbous at their distal ends.

Noxious weed seed categories

State Noxious Weed: Ohio, Pennsylvania 
Federal 

Learn more on ITP's Federal Noxious Weed Disseminules tool.

AOSA examination list

Not included

More information

For more information, see ISMA fact sheet.

Nomenclature

Family

Apiaceae

Valid name

Heracleum mantegazzianum Sommier & Levier

 Heracleum mantegazzianum.  Mericarps with brown longitudinal lines that are bulbous at their distal ends. Photo by Julia Scher, USDA-APHIS-PPQ.
Heracleum mantegazzianum. Mericarps with brown longitudinal lines that are bulbous at their distal ends. Photo by Julia Scher, USDA-APHIS-PPQ.
 Heracleum mantegazzianum.  Mericarps with a scar on the apical end and a winged margin. Photo by Julia Scher, USDA-APHIS-PPQ.
Heracleum mantegazzianum. Mericarps with a scar on the apical end and a winged margin. Photo by Julia Scher, USDA-APHIS-PPQ.
 Heracleum mantegazzianum.  Mericarps with brown longitudinal lines that are bulbous at their distal ends. Photo by Julia Scher, USDA-APHIS-PPQ.
Heracleum mantegazzianum. Mericarps with brown longitudinal lines that are bulbous at their distal ends. Photo by Julia Scher, USDA-APHIS-PPQ.