I noticed these small (less than 0.5 inch) clusters of water fern when I was photographing the surrounding duckweed (Spirodela sp.). Apparently (acc. to ITIS.gov) all the water fern occurring across the southern U.S. is now known as Azolla filiculoides, having previous been known under the names A. caroliniana (e.g. North-Central Flora) or A. microphylla (which BONAP still retains).
Water-race. Azolla, duckweed and Potamogeton cripsum.
I saw this Mosquito Fern in the Killbuck Marsh Wildlife Area.
Wolffia is pictured clinging to the fern.
In the wild.
In the same small pond was this.
Went out again to get closer photos.
Maybe mixture of Water Fern and Lemna Disperma.
Azolla (mosquito fern, duckweed fern, fairy moss, water fern) is a genus of seven species of aquatic ferns in the family Salviniaceae. They are extremely reduced in form and specialized, looking nothing like conventional ferns but more resembling duckweed or some mosses.