ASTERACEAE
Ambrosia trifida
Common Names: Blood Ragweed, Giant Ragweed
leaf--what kind of margin is present here? Most of the time, giant ragweed has three lobes, but can range from one to five lobes (and rarely more than five). | male heads, with staments just about mature (get ready to sneeze!) |
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mature male heads, with anthers exserted (meaning that they are stuck out of the heads), and female heads (these are hard to see--they are beneath the male heads just above the highest leaves). Ragweeds are a major source of Fall hay fever (not goldenrods!). | immature fruits--notice the bracts underneath the fruits |
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mature fruits in Fall, still surrounded by bracts--notice that the male heads have all fallen off, leaving only the rachis of the inflorescence behind. | |