A fern is a plant. A plant is supposed to get pollinated by bees and whatnot. Yet ferns have sperm swimming around and fertilizing the lady-bits of other fern....
Only flowering plants are pollinated by bees and even then not all of them. Ferns evolved before flowers existed so of course they need a different way to breed.
TIL: ferns have sperm that swims (www.thoughtco.com)
A fern is a plant. A plant is supposed to get pollinated by bees and whatnot. Yet ferns have sperm swimming around and fertilizing the lady-bits of other fern....