Hydrilla verticillata

Hydrilla is a submersed, rooted aquatic plant that grows in dense mats in water up to 20 ft. deep. Stem tubers, stem fragments and tubers are the primary means of reproduction.  Stem tubers drop off the plant and successfully survive freezing or drought. The tubers can remain viable for several days out of water and for over four years submerged in sediment. Hydrilla is prohibited in New York; it is illegal to purchase, sell, transport or propagate.