I recently bought a bouquet of flowers for my grandmother a week ago and when i was watering them today I saw these spots on the underside of the leaves. Some of them are black with white tips, and others are white with black little dots in them. I found a few of these spots on the stems of the other flowers. Also, not all of the fern leaves have these spots. I'm unsure if these are spores for the ferns or bug eggs. Please help me. Thank you.