Bacopa monnieri

Bacopa monnieri is one of the most widely distributed aquatic plants in the world, naturally colonising muddy banks, rice paddies, tidal flats, and slow streams across Asia, Africa, Australia, and the Americas. This cosmopolitan distribution reflects its extreme adaptability — it can survive in saline, brackish, and freshwater environments alike, at temperatures ranging from subtropical cool to tropical warm. Its small, succulent, oblong leaves are bright green and arranged in pairs on slender, branching stems. In the aquarium hobby it is used as a lightweight midground or background filler plant whose compact growth habit does not overwhelm smaller tanks. Unlike its cousin Bacopa caroliniana, B. monnieri tends to stay more delicate in appearance and tolerates cooler water, making it suitable for temperate setups. It also has a long history in Ayurvedic medicine as a cognitive herb, adding ethnobotanical interest. In aquariums it provides cover for surface-oriented fish and nano species, and its constant gentle growth makes it a great biological filter supplement in planted tanks.