Perfect for low tek carpets!
Vallisneria nana from Australia is a solitary contrast plant with dark green, rosulate, narrow leaves (less than 1 cm). It is extremely suitable as a mid-ground plant, but can also be used as a background plant in small aquariums. The leaves are much narrower than with other species of Vallisneria, nor are they quite as long.
Vallisneria nana produces offshoots very readily, so compact vegetation will soon develop in good conditions.