Thoreau writes in his journal:
Not only the grass but the pines also were greener yesterday for being wet. To-day, the grass being dry, the green blades are less conspicuous than yesterday. It would seem, then, that this color is more vivid when wet, and perhaps all green plants, like lichens, are to some extent greener in moist weather. Green is essentially vivid, or the color of life, and it is therefore most brilliant when a plant is moist or most alive. A plant is said to be green in opposition to being withered and dead . . .
