Elodea nuttallii Nuttall's Waterweed

An aquatic perennial which is similar to Canadian Waterweed (Elodea canadensis) but with leaves strongly recurved. Like Canadian Waterweed it is a native of North America and was introduced as an aquarium throw-out. All British plants are female. It seems to prefer nutrient-rich water such as disturbed or eutrophicated, slow-flowing canals, ponds, ditches and rivers, where it tends to be more competitive than Canadian Waterweed. It was first recorded wild in Britain in 1966 and has undergone a remarkable vegetative range expansion in much of England in the last 50 years via rooting stem fragments presumably transported by waterfowl. It is common in south Wales and is increasing its range in West Glamorgan, particularly along the canal systems in Neath Port Talbot.

Neophyte