Ludwigia repens also known as Water Primrose, a freshwater aquarium plant originated from North America, it grows up to 20 inches. It is a common plant for freshwater aquarium lovers since it doesn't need much requirements, it can grow on almost any substrate since it has strong roots. In an aquarium it needs fairly bright light. If grown with insufficient light it becomes fully green, but in brighter light it gets a beautiful coppery colour to its leaves and stems. If allowed to, it will grow above the water surface. If given plenty of plant nutrients, it grows rapidly. This rapid growth helps remove the excess Nitrogen that often builds up in aquariums. As with any rapidly growing green plant underwater, their growth is accompanied by the production of Oxygen that is beneficial to fish.