Home / Anomalous_Items / Aquatic_Macrophytes / Submerged_Leaves /Elodea


Click on images for larger format

Name derivation:

elodees (Gr.) – ‘marshy’ or ‘swampy’



Elodea Michaux  1803

Order Hydrocharitales;  Family Hydrocharitaceae



Entirely submerged except flowers that are white or pale purple with three petals. Hydrophyllous pollination occurs on the water surface film.  Stems elongate interminably at the apex to 20-30 cm long, often attaining lengths of more than 3 m, erect; leaves cauline, whorled.  Whorls with 2--4(--7) leaves per node or leaves opposite at most proximal nodes.

Dioecious (separate male and female plants).

Sexual (seed production) and asexual (stem fragmentation) reproduction are common, asexual thought to be dominant.  Only male plants of E. canadensis are present in Australia, so all reproduction is vegetative (asexual) via stem fragments or ‘runners' (stolons).

Similar genera:

Egeria has whorled leaves, 5 or more per node;  Hydrilla has “prickles” on abaxial side of midvein.  (All three genera are in family Hydrocharitaceae.)



Elodea canadensis and E. nuttallii produce toxins that inhibit typical epiphytes, especially cyanobacteria (Erhard and Gross 2006).  Reduction of the epiphybic biofilm increases buoyancy, light intensity and nutrient availability to the host plant.



Widely distributed globally. Freshwater streams, roadside ditches and ponds. Food for several species of fish and birds.  Considered a nuisance invasive that often clogs and covers (‘infests’) its habitat.



Erhard, D., and E.M. Gross  2006.  Allelopathic activity of Elodea Canadensis and Elodea nuttallii against epiphytes and phytoplankton.  Aquatic Botany 85:203-211.