giant hogweed

Apiales > Apiaceae > Heracleum mantegazzianum Sommier & Levier
Giant hogweed is a tall (up to 15-20 ft. [4.6-6.1 m]), herbaceous, biennial plant that invades disturbed areas across both the Northeast and Pacific Northwestern United States. Giant hogweed is designated as a Federal Noxious Weed, because it produces sap that causes skin sensitivity to UV radiation and leads to blistering and severe burns. The large stem is hollow and usually marked with purple blotches. The leaves are deeply lobed, sharply pointed, and up to 5 ft. (1.5 m) wide. Flowering occurs in late spring to early summer. The white flowers are on a large umbrella-shaped head at that can be up to 2.5 ft. (0.8 m) in diameter. Giant hogweed can invade a variety of habitats but prefers moist, disturbed soils such as riverbanks, ditches and railroad right-of-ways. Giant hogweed is native to Europe and Asia. It was first introduced into the United States in 1917 for ornamental purposes.

Identification, Biology, Control and Management Resources

  • Fact Sheet - USDA APHIS PPQ
    http://www.invasive.org/eastern/other/poster_phhogweed.pdf - Apr 18, 2005
  • Weed of the Week - USDA Forest Service
    http://www.na.fs.fed.us/fhp/invasive_plants/weeds/giant-hogweed.pdf - Nov 7, 2006

Selected Images

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Number:1148143
Description: Plant(s);
Photographer:USDA APHIS PPQ Archive, USDA APHIS PPQ
 Additional Resolutions and Image Usage
 
Number:5186078
Description: Foliage;
Photographer:Jan Samanek, State Phytosanitary Administration
 Additional Resolutions and Image Usage
 
Number:1460060
Description: Foliage;
Photographer:Donna R. Ellis, University of Connecticut
 Additional Resolutions and Image Usage
 
Number:2121077
Description: Plant(s);
Photographer:Thomas B. Denholm, New Jersey Department of Agriculture
 Additional Resolutions and Image Usage
 
Number:5272015
Description: Feature(s); Stem cross-section
Photographer:Leslie J. Mehrhoff, University of Connecticut
 Additional Resolutions and Image Usage
 
Number:5272019
Description: Stem(s);
Photographer:Leslie J. Mehrhoff, University of Connecticut
 Additional Resolutions and Image Usage
 
Number:1460062
Description: Plant(s);
Photographer:Donna R. Ellis, University of Connecticut
 Additional Resolutions and Image Usage
 
Number:0015002
Description: Fruit(s);

Mericarp (7)9-12 mm long x 6-8(10) mm broad, strongly flattened dorsally

Photographer:USDA APHIS PPQ Archive, USDA APHIS PPQ
 Additional Resolutions and Image Usage
 
Number:1237083
Description: Seed(s);
Photographer:USDA APHIS PPQ Archive, USDA APHIS PPQ
 Additional Resolutions and Image Usage
 
Number:5272018
Description: Fruit(s);
Photographer:Leslie J. Mehrhoff, University of Connecticut
 Additional Resolutions and Image Usage
 
Number:5186072
Description: Fruit(s);
Photographer:Jan Samanek, State Phytosanitary Administration
 Additional Resolutions and Image Usage
 
Number:1151039
Description: Flower(s);
Photographer:Terry English, USDA APHIS PPQ
 Additional Resolutions and Image Usage
 
Number:1148089
Description: Flower(s);
Photographer:USDA APHIS PPQ Archive, USDA APHIS PPQ
 Additional Resolutions and Image Usage
 
Number:2121076
Description: Flower(s);
Photographer:Thomas B. Denholm, New Jersey Department of Agriculture
 Additional Resolutions and Image Usage
 
Number:5186075
Description: Infestation; in flower
Photographer:Jan Samanek, State Phytosanitary Administration
 Additional Resolutions and Image Usage
 
Number:1148145
Description: Infestation;
Photographer:USDA APHIS PPQ Archive, USDA APHIS PPQ
 Additional Resolutions and Image Usage
 
Number:2137089
Description: Infestation; In winter
Photographer:Barbara Tokarska-Guzik, University of Silesia
 Additional Resolutions and Image Usage
 
Number:1299163
Description: Plant(s);
Photographer:Randy Westbrooks, U.S. Geological Survey
 Additional Resolutions and Image Usage
 
Number:1148090
Description: Damage;

Burn caused by plant (left leg, person lying down)

Photographer:USDA APHIS PPQ Archive, USDA APHIS PPQ
 Additional Resolutions and Image Usage
 
Number:1151079
Description: Control;
Photographer:Terry English, USDA APHIS PPQ
 Additional Resolutions and Image Usage
 
Number:2121079
Description: Control;
Photographer:Thomas B. Denholm, New Jersey Department of Agriculture
 Additional Resolutions and Image Usage
 

External Links

Invasive Reference(s)

Subject Reference(s)

  • USDA, NRCS. 2001. The PLANTS Database, Version 3.1, National Plant Data Center, Baton Rouge, LA 70874-4490 USA. - http://plants.usda.gov/