This is an aquatic plant. Do you have it in a pond or a pot. If it is in a pond, copper will kill any invertebrates.
It looks like black sooty mold which should never occur in sunlight. Other than that, I can't really say.
This is an aquatic plant. Do you have it in a pond or a pot. If it is in a pond, copper will kill any invertebrates.
It looks like black sooty mold which should never occur in sunlight. Other than that, I can't really say.