Great or Giant Ragweed,
Ambrosia trifida
Asteraceae or Sunflower Family
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Very tall herb, up to 15 feet tall. Leaves
deeply divided into three lobes. Flowers tiny, in
crowded spikes at the top of the plant, green. Blooms in
late summer
Common native plant of moist places. Much despised because its pollen, along with that of common ragweed, is the principal cause of autumn hayfever. Common ragweed (Ambrosia artemisiifolia)
has similar flowers (that also cause hayfever), but it is much
smaller and its leaves are deeply dissected into many small
segments. |
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