Not a botanist, but their tadpoles swim. Plants without this feature will relocate the sperm themselves.

e: As a result of learning this, I also learned that molluscs, arthropods, and vertebrates all evolved brains independently, and it's actually normal for molluscs to have distributed brains rather than it being a neat quirk of a few examples. Arthropod brains are also more or less distributed depending on their specific needs.

I studied biology and one thing I like about ferns is that they have these "dots" under their "leaves" that once mature drops a powder of spores that creates new ferns... Don't ask me why I like it, I just do. I find it simple and to the point. You can simply leave a pot with earth under a fern and then you will find a baby developing there. Just like magic, and very elegant.

idk if there are other cool parts, but the one i'm aware of is that their jizzulate is asexual, basically clones (i think). The ferns shed spores which grow into what looks like a leaf on the ground, then those "leaves" have their own more normal sex cells which do the usual thing, which then grow into actual ferns from the surface of the "leaf".
It's fucking wild.