Pollinometers

June 21.

June 21, 2013

Having noticed the pine pollen washed up on the shore of three or four ponds in the woods lately and at Ripple Lake, a dozen rods from the nearest pine, it suggested to me that the air must be full of this fine dust at this season, that it must be carried to great distances, and its presence might be detected remote from pines by examining the edges of bodies of water, where it would be collected to one side by the wind and waves from a large area. The time to examine the ponds this year was, I should say, from the 15th to the 20th of this month.

As chemists detect the presence of ozone in the atmosphere by exposing to it a delicately prepared paper, so the lakes detect for us thus the presence of the pine pollen in the atmosphere. They are our pollinometers.

A large pond will collect the most, and you will find most at the bottom of long deep bays into which the wind blows.

How much of this invisible dust must be floating in the atmosphere, and be inhaled by us at this season!! I do not believe that there is any part of this town on which the pollen of the pine may not fall.

H. D. Thoreau, Journal, June 21, 1860

See June 21, 1850 ("The flowers of the white pine are now in their prime, but I see none of their pollen on the pond."); June 21, 1856 ("Much pine pollen is washed up on the northwest side of the pond. Must it not have come from pines at a distance?"); See also May 4, 1853 ("Humboldt speaks of its having been proved that pine pollen falls from the atmosphere."); June 3, 1857 ("The pitch pine at Hemlocks is in bloom. . . .As usual, when I jar them the pollen rises in a little cloud about the pistillate flowers and the tops of the twigs, there being a little wind");June 9, 1850 ("I see the pollen of the pitch pine now beginning to cover the surface of the pond. Most of the pines at the north northwest end have none, and on some there is only one pollen-bearing flower. "); June 14, 1853 ("The pollen of the pine yellowed the driftwood on the shore and the stems of bushes which stood in the water, and in little flakes extended out some distance on the surface, until at four or five rods in this cove it was suddenly and distinctly bounded by an invisible fence on the surface");  June 14, 1854 ("Bacon says he has seen pitch pine pollen in a cloud going over a hill a mile off;");June 18, 1860 ("I see in the southerly bays of Walden the pine pollen now washed up thickly; only at the bottom of the bays, especially the deep long bay, where it is a couple of rods long by six to twenty-four inches wide and one inch deep; pure sulphur-yellow, and now has no smell. It has come quite across the pond from where the pines stand, full half a mile, probably washed across most of the way."); June 20, 1858 ("Walking in the white pine wood there, I find that my shoes and, indeed, my hat are covered with the greenish-yellow pollen of the white pines, which is now being shed abundantly and covers like a fine meal all the plants and shrubs of the forest floor.");  June 22, 1858 ("I notice, after tipping the water out of my boat under the willows, much evidently pine pollen adhering to the inside of the boat along the water-line. Did it fall into it during my excursion to Holden’s Swamp the 20th, or has it floated through the air thus far?"); June 25, 1852 ("I am too late for the white pine flowers. The cones are half an inch long and greenish, and the male flowers effete.”);  June 25, 1857 ("White pine effete. "); June 25, 1858 ("The ground under the white pines is now strewn with the effete flowers, like an excrement.”); July 1, 1852 ("The path by the wood-side is red with the effete staminiferous flowers of the white pine.")