Small round brown spots on back of fern

Question

What is the cause of small brown spots on the back-side of what I think is wood fern or some kind of fern? Is it a pest egg or part of the plant? The spots are symmetrical up and down the leaf.

Answer 1

I believe what you are seeing are spores. Rather than using flowers or fruits for reproduction, ferns produce by spores. The spores of most ferns show up as dark spots on the back of each leaf.