in Thoreau’s Journal:
A warm, drizzling day, the tender yellow leafets now generally conspicuous, and contrasted with the almost black evergreens which they have begun to invest. The foliage is never more conspicuously a tender yellow than now. This lasts a week from this date, and then begins to be confounded with the older green. We have had rain for three or four days, and hence the tender foliage is the more yellow.