Callitriche

Callitriche is in many of the ditch puddles this time of the year. The species is likely C. vernalis. It will go to seed and die out soon and spend the hot summer months as seeds. I don't think it has been investigated very much to see how suitable it is as an aquarium plant. It clearly is aquatic. In fact, it is one of the few aquatics that has underwater polllination. Others that do this are Ceratophyllum and Didiplis.