Hydrilla (Hydrilla verticillata), also called water thyme, is an invasive aquatic plant native to Africa and Southeast Asia. It has now made its way to Canada and the southern and eastern U.S. "It ...

Hydrilla verticillata (L. fil.) Royle, an immigrant submersed weed from Asia. Field populations of P. diminutalis are occasionally heavy on hydrilla but are rarely found on other plant species, ...