Better known as Canadian waterweed or pondweed, this aquatic plant has been around since 1836!
The leaves are bright green, translucent, about 15mm long and 1-4mm broad. It lives entirely underwater. In ideal conditions, it grows quickly and requires moderate lighting and water from 10-25C making it ideal for ponds in the summer.It looks a bit like Egeria densa and you can propagate by cuttings quite easily. Any excess plants you do not want, discard in your recycling bin.
The picture is copyright of Christian Fisher and shows the plant up close. You will receive 5-6 stems.