giant ragweed

(Ambrosia trifida var. trifida)

               
Conservation Status

IUCN Red List

not listed

giant ragweed

NatureServe

N5? - Secure

SNR - Unranked

Minnesota

not listed

Wetland
Indicator
Status

Great Plains

FAC - Facultative

Midwest

FAC - Facultative

Northcentral & Northeast

FAC - Facultative

Nativity

Native

Occurrence

Common

Habitat

Moist soil. Disturbed sites, fields, roadsides.

Flowering

August to September

     
Flower Color

Green

     
Height

2 to 9

     
 
Identification

This plant is easily distinguished from other ragweeds by its large size and palmately-lobed leaves.

 
Similar
Species

The leaves of other ragweeds are pinnatifid (western ragweed) or bipinnatifid (common ragweed).

 
Distribution Distribution Map   Sources: 2, 3, 4, 5, 7, 28.
 
Comments

 

 
Taxonomy

Family:

Asteraceae (aster)

 

Subfamily:

Asteroideae

 

Supertribe:

Helianthodae

 

Tribe:

Heliantheae (sunflower)

 

Subtribe:

Ambrosiinae

 
Synonyms

Ambrosia trifida var. integrifolia

 
Common
Names

giant ragweed

great ragweed

 

 

 

 

 

 

 

 

 

Glossary

Palmately Lobed

Similar to a hand. Having more than three lobes that radiate from a single point at the base of the leaf.

 

Pinnatifid

Deeply cut, more than half way to the midrib but not to the midrib, into lobes that are spaced out along the midrib; the lobes do not form separate leaflets.

       
Visitor Photos
   
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MinnesotaSeasons.com Photos
   

Plant

  giant ragweed   giant ragweed
       
  giant ragweed   giant ragweed
       

Inflorescence

  giant ragweed   giant ragweed
       

Flower Heads

  giant ragweed    
       

Leaves

  giant ragweed   giant ragweed
       

Early Spring

  giant ragweed   giant ragweed
       
       

 

Camera

     
Slideshows
   
  Giant Ragweed (Ambrosia trifida)
Bill Keim
 
  Giant Ragweed (Ambrosia trifida)  
     
  Ambrosia trifida GIANT RAGWEED
Frank Mayfield
 
  Ambrosia trifida GIANT RAGWEED  

 

slideshow

       
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Other Videos
 
  Giant Ragweed - University of Missouri
MU Plant Sciences
 
   
 
About

Uploaded on Feb 28, 2012

Giant Ragweed, MU Weed Science, University of Missouri

   
       
  Greenhouse Giant Ragweed .m4v
Ohio State University Weed Science
 
   
 
About

Uploaded on Feb 22, 2012

Dr. Mark Loux from The Ohio State University talks about herbicide resistant giant ragweed research being done in the university greenhouses.

   
       
  Weed of the Week #790 - Giant Ragweed (Air Date 5/26/13)
AgPhD
 
   
 
About

Published on Jun 4, 2013

It's our Weed of the Week, Giant Ragweed.

   
       

 

Camcorder

         
Visitor Sightings
   
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Terry Pfleghaar
8/5/2018

Location: Elk River, MN

I allowed this to grow in my garden, not knowing what it was. I finally was able to identify it when it was about 10’ tall!


     
     
 
MinnesotaSeasons.com Sightings
         

Baker Park Reserve

Bertram Chain of Lakes Regional Park

Blaine Preserve SNA

Blue Mounds State Park

Bur Oak WMA

Carpenter St. Croix Valley Nature Center

Carver Highlands WMA, South Unit

Carver Park Reserve

Cedar Mountain SNA

Cedar Rock SNA

Cherry Grove Blind Valley SNA

Compass Prairie SNA

Cottonwood River Prairie SNA

Crosby Farm Regional Park

Crow-Hassan Park Reserve

Des Moines River SNA

Dodge Nature Center

Elm Creek Park Reserve

Falls Creek SNA

Felton WMA

Forestville/Mystery Cave State Park

Franconia Bluffs SNA

French Regional Park

Frontenac State Park

Glacial Lakes State Park

Glynn Prairie SNA

Great River Bluffs State Park

Hastings SNA

Hayes Lake State Park

Holthe Prairie SNA

Hyland Lake Park Reserve

Hythecker Prairie SNA

Iron Horse Prairie SNA

Joseph A. Tauer Prairie SNA

Kasota Prairie SNA

Kellogg Weaver Dunes SNA, Kellogg Weaver Unit

Kilen Woods State Park

King’s and Queen’s Bluff SNA

Lake Louise State Park

Lake Rebecca Park Reserve

Lebanon Hills Regional Park

Liable Woods

Lost Valley Prairie SNA

Lundblad Prairie SNA

Malmberg Prairie SNA

Mary Schmidt Crawford Woods SNA

McKnight Prairie

Minneopa State Park

Minnesota Valley NWR, Louisville Swamp Unit

Minnesota Valley NWR, Rapids Lake Unit

Minnesota Valley NWR, Wilkie Unit

Minnesota Valley State Recreation Area, Lawrence Unit

Morton Outcrops SNA

Mound Prairie SNA

Mound Spring Prairie SNA, North Unit

Myre-Big Island State Park

Northern Tallgrass Prairie NWR, Spieker Unit

Ordway Prairie

Oronoco Prairie SNA

Osmundson Prairie SNA

Oxbow Park & Zollman Zoo

Partch Woods SNA

Pine Bend Bluffs SNA

Prairie Coteau SNA

Prairie Creek WMA, Koester Prairie Unit

Racine Prairie SNA

Red Rock Prairie

Rice Lake State Park

River Terrace Prairie SNA

River Warren Outcrops SNA

Robert Ney Memorial Park Reserve

Rock Ridge Prairie SNA

Rockville County Park

Rushford Sand Barrens SNA

St. Croix Savanna SNA

Sandpiper Prairie SNA

Savage Fen SNA

Schaefer Prairie

Seminary Fen SNA

Seven Springs WMA

Shooting Star Prairie SNA

Split Rock Creek State Park

Spring Lake Park Reserve

Swedes Forest SNA

Tiedemann WMA

Tympanuchus Prairie

Uncas Dunes SNA

Upper Sioux Agency State Park

Vermillion River WMA

Wahpeton Prairie WMA

Western Prairie SNA

Whitetail Woods Regional Park

Whitewater State Park

Wild Indigo SNA

Woodbury WMA

Yellow Bank Hills SNA

 

 

Binoculars


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