Ragweed, or Great ragweed (Ambrosia trifida)
 
 
 

 

Photo below by Jeff McMillian @ USDA-NRCS PLANTS Database

Ragweed (Great ragweed) is part of the Asteraceae (Aster) family and is notorious for the hay fever caused by their irritating airborne pollen.  The common name for Ambrosia trifida is Giant ragweed and it is a coarse annual weed.  The plants are usually hairy and can grow to 3 feet tall, but are usually less than 1 foot tall, with leaves deeply divided into many narrow lobes.  Tiny, drab flowers point downward and are inconspicuous. 

Ragweed blooms midsummer to fall and is common in moist soil and waste places in our region of the country.


 

Additional information about this plant may be found at the USDA PLANTS Database:

http://plants.usda.gov/java/profile?symbol=AMTR