A cold storm still, — the most serious storm since spring.

August 30. 

A cold storm still, — this the third day, — and a fire to keep warm by. This, methinks, is the most serious storm since spring. 

Polygonum amphibium var. aquaticum, which is rather rare. I have not seen it in flower. It is floating. 

Its broad heart-shaped leaves are purplish beneath, like white lily pads, heart-leaves, and water-targets. What is there in the water that colors them? 

The other variety, which [is] rough and upright, is more common, and its flowers very beautiful.

H. D. Thoreau, Journal, August 30, 1852

A cold storm still, — this the third day, — the most serious storm since spring. See August 25, 1852 ("The cricket sounds louder, preparatory to a cheerful storm! How grateful to our feelings is the approach of autumn! We have had no serious storm since spring."); August 29, 1852 ("A warm rain-storm in the night, with wind, and to-day it continues."); August 31, 1852 ("It is worth the while to have had a cloudy, even a stormy, day for an excursion, if only that you are out at the clearing up.")

Polygonum amphibium.  [Water Smartweed] See  August 5, 1856 ("Polygonum amphibium in water, slightly hairy, well out."); August 19, 1858 ("Large, handsome red spikes of the Polygonum amphibium are now generally conspicuous along the shore."); September 18, 1856 ("I have seen no . . . Polygonum amphibium var. aquaticum . . .this year.");  September 22, 1852 ("The Polygonum amphibium var. terrestre is a late flower, and now more common and the spikes larger, quite handsome and conspicuous, and more like a prince's-feather than any.") See also September 1, 1857 ("I have finally settled for myself the question of the two varieties of Polygonum amphibium. I think there are not even two varieties. "); September 18, 1858 ("The perfectly fresh spike of the Polygonum amphibium attracts every eye now. It is not past its prime. C. thinks it is exactly the color of some candy."); September 27, 1858 ("The P. amphibium spikes still in prime. "); October 16, 1858 ("I see some Polygonum amphibium, front-rank,"); November 7, 1855 ("How completely crisp and shrivelled the leaves and stems of the Polygonum amphibium var. terrestre, still standing above the water and grass!")