Proserpinaca palustris

Proserpinaca is a stem plant, 10-40 cm tall and 5-10 cm wide. 
Cultivated in closed cups and delivered with saw-toothed leaves, which after a transitional period in the aquarium develop into long, finely denticulated, needle-like leaves. 
In good light conditions it turns a beautiful copper colour and its characteristic appearance is a pleasing contrast to the other plants. 
Proserpinaca palustris varies in form according to its origin. The Tropica cultivar is found on the Isla de la Juventud off Cuba. In the USA the plant is commonly known as "mermaid weed''.