One Cup Azolla caroliniana

 Azolla caroliniana started showing up in my Duckweed grow beds It is a much darker green than Duckweed Azolla turns to a beautiful rusty red as it matures. Tilapia eat it, but all fish love it's shade. 

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 other typical ferns but more resembling duckweed or some mosses. Wikipedia