Photographs: The Gearagh, Co. Cork

Nuttall's Waterweed Elodea nuttallii Tím uisce chaol Family: Hydrocharitaceae Submerged aquatic perennial. Garden escape. Introduced. Minute dioecious flowers are present but all reproduction is vegetative as only female plants occur in Ireland and Britain. Plants are very similar to Canadian Pondweed but the leaves are narrower, longer, more acute and often twisted. Usually in whorls of 4. The fresh root-tips are white to grey-green. Stems to 3m. Identified by Paul Green A garden escape that is a rapid coloniser of still or slow-moving shallow or deep water. The first Irish record was at Lough Neagh in 1984 and it is now designated a significant invasive plant in Ireland.

Nuttall's Waterweed, Elodea nuttallii, Tím uisce chaol