Hydrilla
Other Common Names: Florida Elodea, water thyme, Indian star-vine
(Hydrilla verticillata)
Non-Native
Hydrilla is a rooted submerged plant with whorled green leaves that have tiny teeth.
Description
Hydrilla has pointed bright green leaves in whorls of four to eight. Leaves are one-eighth to three-eighths of an inch long.
One or more sharp teeth along the midrib make the leaves feel rough when this plant is run through the hand from base to tip. Some leaves float but most are submerged.
The slender stems can grow to 25 feet long and are branched. This plant is typically rooted; however, it can also live as a mat free floating on the surface of the water.
Hydrilla is sometimes confused for Elodea but can be distinguished by one or more teeth on the underside of the leaves and the presence of tubers.
Hydrilla can form dense colonies, branching profusely after reaching the surface. Hydrilla is easily fragmented, and more plants will grow from those fragments.
Hydrilla is extremely hearty and can grow in a wide variety of water conditions, including as low as 1% of full sunlight. It is possible for a mass of Hydrilla to double in size every two weeks in the summer.
Management Options
Location
Hydrilla can be found in Washington, California, Arizona, and the gulf, southeastern, and eastern states.
Propagation
fragments, roots, tubers