Bacopa is a genus of 70 – 100 aquatic plants belonging to the family Plantaginaceae. It is commonly known as Waterhyssop(or Water Hyssop, though this is more misleading as Bacopa is not very closely related to hyssop but simply has a somewhat similar appearance).
They are annual or perennial, decumbent or erect stemmed plants. The leaves are opposite or whorled, sessile. Leaf blade regular, round to linear, venation palmate or pinnate. Stems hairy or smooth. The flowers are produced solitary or in pairs from leaf axil, usually radially symmetrical, sepals 5, petals 5, usually white, blue or purple in color. Dispersal and propagation is by seeds and stem fragments. Crushed leaves have a distinctive ‘lemon’ scent.
Habitat and range
Bacopa species are found in tropical and subtropical regions of the world, particularly theAmericas. 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. myriophylloidesseem to be wholly aquatic.
Bacopa monnieri syn. Herpestis monniera, is important in Ayurvedic medicine and has been used, particularly in India, for several thousand years to improve mental functioning, including comprehension (Dhi), memory (Dhriti), and recollection (Smriti).
Some of these species are commonly used in freshwater aquariums and around and in ponds in warmer climates. Most are easy to grow and are slow-growing, but require medium to high amounts of light. Most are easy to grow and will tolerate a wide range of water conditions. B. caroliniana at least will tolerate brackish water. Plants are usually best planted in groups in the middle to background. Algal infestation can be a problem in brighter lighting condition.