Egeria densa Large-flowered Waterweed

A native of South America which is grown by aquarists and has become widely naturalised as an aquarium escape in many parts of the world. It is an evergreen perennial, somewhat like Hydrilla (Hydrilla verticillata) but with white flowers which are about 1cm in diameter and most if not all plants in Britain are probably male. It usually grows submerged in canals and in waters that are subject to warming. It has a thinly scattered distribution in Britain and it was only recently discovered in West Glamorgan by BS in Port Talbot Docks.

Neophyte