Azolla caroliniana, also known as mosquito fern, is a floating, aquatic fern native to the North, South, & Central America. It is a free-floating fern measuring less than ½ inch across. Newer leaves are gray green, but can turn rusty-red, especially in winter. It spreads vegetatively and can quickly form large, floating mats. This little fern is also useful as a floating plant in aquariums, where it can provide good cover for fry or for jumpy fish.
