Hi, everybody. I saw a post similar to this but couldn't really make sense of the conclusions so I'll start a new topic.

The spinach I planted is beginning to mature and I've noticed some tiny white specks on the leaves. They're on the top side of the leaves and can't be brushed off. I have to pick them out. I don't have anything to magnify them with so it's hard to tell what they are. Since they're not just granules on the surface, I don't think they're calcium oxalate crystals. And since they're on the top side and not totally lined up, they don't seem like leaf miner eggs. They seem to be clustered near the edges of the leaves. What could this be? I'll post a close-up pic.