- any of the composite plants of the genus Ambrosia, the airborne pollen of which is the most prevalent cause of autumnal hay fever, as the common North American species, A. trifida (great ragweed or giant ragweed) and A. artemisiifolia.
Origin of ragweed
Examples from the Web for ragweed
Historical Examples of ragweed
Yellow-stick, the ragwort or ragweed, which grows to a great size in Ireland.The Fairy Mythology
Then there's this ragweed; if I let it alone, it will choke out every thing else.The Old Market-Cart
Mrs. F. B. Smith
If man could make but the single seed of the ragweed, he could make a world.
"Honestly, I didn't think it would kill anything but ragweed," Henry sniveled miserably.Henry Horn's X-Ray Eye Glasses
Dwight V. Swain
Weed seeds such as those of spurges (Euphorbia), ragweed, and pigweed were found in trace amounts in the diet of the crows.
- any plant of the chiefly North American genus Ambrosia, such as A. artemisiifolia (common ragweed): family Asteraceae (composites). Their green tassel-like flowers produce large amounts of pollen, which causes hay feverAlso called: ambrosia
- Any of various weeds of the genus Ambrosia having small greenish unisexual flower heads and producing abundant pollen that is one of the chief causes of hay fever.