Sneezing? Runny nose? Sinus headache? Those have recently been my symptoms too. I've been mistakenly laying the blame on the many species of now flowering Goldenrods. Posts on the Goldenrods are in the works but for today lets look at the real cause of hay fever--Ragweed, Ambrosia artemisiifolia.
Compared to the entomophilous goldenrods, ragweeds are wind-born pollinators. My own observations have proved that out--bees are numerous over the goldenrods while disregarding the ragweeds. (I'd been wondering where the bees were at lately, as I've been following them as various species come into and out of flower. A fascinating endeavor of its own...)
All that fine and blown about pollen makes its way into everything, including us. It's not clear to me on how wide is the window on ragweed pollen production. I wonder if wind and rain help to clear it out? As always, small discoveries lead to more questions, and that's what keeps this all so exciting! :-)
From The Writings of John Burroughs:
"Of our ragweed not much can be set down that is complimentary, except that its name in the botany is Ambrosia, food of the gods. It must be the food of the gods if anything, for, so far as I have observed, nothing terrestrial eats it, not even billy-goats."
Burroughs, John. The Writings of John Burroughs, Volume 8. Boston, New York, 1895. 201. Web. Google Book Search. 7 Sep 2009.