Hydrilla (Hydrilla)

Hydrilla is a submersed aquatic plant in the Hydrocharitaceae family. Native to Africa and Asia, Hydrilla has become one of the most impactful invasive species in the southeastern United States, but has not yet been found within Oregon. Hydrilla can easily fragment and spread rapidly through an aquatic system.

Hydrilla looks very similar to other submersed Hydrocharitaceae representatives. Brazilian elodea (Egeria densa) and Canadian elodea (Elodea canadensis) are both found within Oregon and may be confused with Hydrilla. Hydrilla can be identified by usually having five leaves to a whorl and the spiny or toothed mid-rib and leaf margins, as well as distinct tubers. Egeria densa (brazilian elodea) can be identified by typically having four leaves per whorl that are 10-40mm long with finely  serrated leaf margins. Canadian elodea possesses three leaves per whorl and can either have minute serrations or lack serrations. Both Brazilian elodea and Canadian elodea lack tubers.