Anacharis is an oxygenating plant that grows beneath the surface of the water with narrow green leaves on long green stems. Anacharis is sold in bunches. Anacharis helps in algae elimination by competing for the same nutrients that algae needs to thrive, while adding oxygen to the water.
AL, CA, CT, ID, IL, IN, LA, MA, ME, MI, MN, MS, MT, NE, NH, NY, OH, OR, PR, SC, VT, WA, WI
Note there is a similar plant, Anacharis canadensis along with many other great submerged oxygenating plants that are legal and more winter hardy.
Hornwort which is legal, more cold tolerant, and better at nutrient uptake than Anacharis.