black-knot

Updated: September 20, 2025

When this fails, she will no longer hit the mark or try to hit it. Let there be a plum tree anywhere with the disease called the "black-knot" upon it, and presently every plum tree in its neighborhood will have black knots. Do you think the germs from the first knot knew where to find the other plum trees?

John Burroughs - Ways of Nature