Ragweed.
"{W}we had to conclude that something in the September combination of waning sun and increased humidity released vapors a stronger sun or an earth more parched would have beaten down or imprisoned and that the fragrance was indeed a distillation of all the things it suggested --- of the late flowers in the meadows and the low, matted tangle of the half-rotted undergrowth, of the turning grape and of the falling apple and of the ragweed and the breath of the trees and the September rose and of the ripe brown body of Autumn herself.''
-- From In Praise of Seasons, by the late Alan J, Olmstead, a Connecticut newspaper editor and an essayist.
