What is this and what causes it? I cut off all the leaves affected. I could do that because it's a small lychee plant in a 5 gallon container. I will plant it in our back yard when we clear enough space for it. For now, it's in the bucket.
Thanks Imafan. Yup, it looks like the pictures. I got rid of all the infected leaves, and I'll watch the plant more carefully and pick off any infected leaves as soon as they appear.