Ambrosia trifida

Common Name: 
giant ragweed, great ragweed
Scientific Name: 
Ambrosia trifida L.
Family Name: 
Asteraceae (Compositae) - Aster or Sunflower Family
Identification Notes
Life Cycle
native annual, reproducing by seed
Seeds of Giant Ragweed
Stems
Stems of Giant Ragweed
Stems of Giant Ragweed
Stems of Giant Ragweed
Stems of Giant Ragweed
Stems of Giant Ragweed
Leaves
opposite and three lobed (sometimes 4 or 5, 4th and 5th small), large, rough- surfaced; upper leaves lanceolate, no lobes
Leaves of Giant Ragweed
Leaves of Giant Ragweed
Flowers
heads of green disc (tubulate) florets; male flowers in inverted receptacle, terminal racemes; female flowers axillary above
Flowers of Giant Ragweed