Guttation is NOT dew. Dew (condensation from vapour) would give no hint that the growing season had begun; guttation does.
I have often marked the beginning of spring with a picture of guttation—to me the best indication that plants have begun to metabolize. It is a sign that the plant—in this case grass—is pumping xylem fluid from the roots to the leaves. During the day, such fluid is transpired. However, on a cold night, the stomata have closed and the fluid is extruded through the tip of the blade (at a hydathode) to give guttation.
On earlier occasions, I would often lie on the grass and take a macro image of the guttation drops, each hanging from the tip of the grass blade. On this occasion, the striking nature of this backlit image was more compelling.
Guttation: spring is underway.
I did not know that guttation applied to plants. I have taken many photos of guttation in mushrooms. I really enjoy your posts and learn a lot from them. Thank you for this.