Signs of Fall

August 23.

6 a.m. — To Nawshawtuct. A very clear but cool morning, all white light. The feverwort berries are yellowing and yellowed; bar berries have begun to redden, and the prinos, — some of the last quite red. August has been thus far dog-days, rain, oppressive sultry heat, and now beginning fall weather.

P. M. — Clematis Brook. By the side of the brook that comes out of Deacon Farrar's Swamp and runs under the causeway east of the Corner Bridge the great bidens flowers are all turned toward the westering sun like sun flowers, hieroglyphics of the seasons. I go there as to one of autumn's favorite haunts. Most poems, like the fruits, are sweetest toward the blossom end. 

The milkweed leaves are already yellowing. A solidago some time out, say a week, on side of Mt. Misery. Looking down the river valley now from Mt. Misery, an hour before sundown, I am struck with nothing so much as the autumnal coolness of the landscape and the predominance of shade.

H. D. Thoreau, August 23, 1853

The feverwort berries are yellowing and yellowed. See Septmeber 6, 1859 ("The feverwort berries are apparently nearly in their prime, of a clear "corn yellow " and as large as a small cranberry, in whorls at the axils of the leaves of the half- prostrate plants. ")
An hour before sundown. See  The hour before sunset.