Re: anacharis distinction in U.S. The "anacharis" commonly sold through pet/aquarium stores is usually the egeria densa -- the elodea canadensis has a much smaller leaf and is a more brittle plant. Also, the canadensis has a tiny purple bloom while the egeria has a white one. In the temperate pond outdoors, the elodea c. breaks dormancy nearly a month earlier. The koi think it's a super plant. Helen Nash