Bluets whiten the fields, and violets are now perhaps in prime.

May 21

P. M. —To Island. 

Salix nigra leafs. 

Is that plump blue-backed, rufous rumped swallow the cliff swallow, flying with barn swallows, etc., over the river? Nuttall apparently so describes it. It dashes within a foot of me. 

Lambkill leaf, a day or two. Choke-berry pollen; perhaps a day or more elsewhere. Viola palmata pretty common, apparently two or three days. Some button bush begins to leaf. Cranberry well started; shoots three quarters of an inch. 

dog-tooth violet
May 21, 2017

Bluets whiten the fields, and violets are now perhaps in prime. 

Very cold to-day; cold weather, indeed, from the 20th to 23d inclusive. Sit by fires, and sometimes wear a greatcoat and expect frosts.

H. D. Thoreau, Journal, May 21, 1855

Is that plump blue-backed, rufous rumped swallow the cliff swallow, flying with barn swallows, etc., over the river? See April 30, 1856 ("I was surprised by the great number of swallows—white-bellied and barn swallows and perhaps republican — flying round and round, or skimming very low over the meadow. . .There were a thousand or more of swallows, and I think that they had recently arrived together on their migration.");  May 4, 1856 (“Among others, I see republican swallows flying over river at Island”); May 11, 1856 ("There are many swallows circling low over the river behind Monroe’s, — bank swallows, barn, republican, chimney, and white-bellied. These are all circling together a foot or two over the water, passing within ten or twelve feet of me in my boat."); May 20, 1858 (“Hundreds of swallows are now skimming close over the river. . .. There are bank, barn, cliff, and chimney swallows, all mingled together.”); May 20, 1858 (“The cliff swallow, then, is here.”)

Lambkill leaf, a day or two. See May 26, 1855 ("The lambkill is just beginning to be flower-budded");  June 9, 1855 ("Lambkill out"); .June 10, 1855 ("The Kalmia glauca is done before the lambkill is begun here."); June 13, 1852 ("Lambkill is out. I remember with what delight I used to discover this flower in dewy mornings."); );June 13, 1854 ("How beautiful the solid cylinders of the lamb-kill now just before sunset, ") See also A Book of the Seasons, by Henry Thoreau, Lambkill (Kalmia augustifolia)

Bluets whiten the fields, and violets are now perhaps in prime. See May 7,1860 ("I saw bluets whitening the fields yesterday a quarter of a mile off. They are to the sere brown grass what the shad-bush is now to the brown and bare sprout lands."); May 14, 1852 ("The grass is now whitened with bluets; the fields are green.")

Very cold to-day; cold weather, indeed. See May 21, 1860 (“Cold, at 11 A.M. 50°; and sit by a fire”)