Bacopa

Bacopa monnieri in Hyderabad, India.

They are annual or perennial, with decumbent or erect stems. The leaves are opposite or whorled, and sessile. The leaf blade is regular, round to linear, and the venation is palmate or pinnate. Its stems are hairy or smooth. The flowers are produced solitary or in pairs from leaf axils, usually radially symmetrical, with five sepals and five petals, and they are usually white, blue, or purple. Dispersal and propagation is by seeds and stem fragments. Crushed leaves have a distinctive 'lemon' scent.

Bacopa myriophylloides

Bacopa species are found in tropical and subtropical regions of the world, particularly the Americas. A few are regarded as weeds and excess stock should not be dumped in warmer regions. Most grow in moist amphibious conditions, though some like B. myriophylloides seem to be wholly aquatic.

Bacopa monnieri is used in Ayurvedic medicine. Preliminary clinical research found that the herb may improve cognition.[2][3][4]

Some of these species are commonly used in freshwater aquariums and ponds in warmer climates. Most are easy to grow and will tolerate a wide range of conditions. B. monnieri will tolerate brackish water up to 15 ppt, due to specialized adaptations it can employ to survive in saline environments, while B. caroliniana does not appear to have the same tolerance. Algal infestation can be a problem in brighter lighting conditions.[5][6][7]

• Chaenostoma cordatum syn. Sutera cordata, a plant also known by the obsolete name Bacopa.