Hey, guys. I just joined this forum, as I cannot find the name of this plant blight.
At the time, I cannot post a picture, but I will make sure I will within the day.
My lettuce and cucumber plants developed insanely small black spots, about the size of the root of a hair.
The spots did nothing at first, but I noticed they started to develop groups of spots. The group of spots caused a dead portion of the plant to form around it. The lettuce remained fine, just with the spots and small dead parts, but the cucumber caused wilting on all affected leaves within two weeks.