Bacopa is a family of plants that are classified as herbaceous perennials. These low-growing, spreading plants, which have succulent leaves, are often simply called "water hyssop," regardless of the particular type. This common name was probably given in part because the plant is often found partially submerged in still waters. Historically, Bacopa plants have been valued for their medical properties, according to the Northwest Times of Indiana website.
There as many as 100 species of Bacopa plants, according to the Aquatic and Pond Plants of the World website, but only one, B. caroliniana, is actively cultivated in America. Another, B. routundiflora, is native to North America and is found growing wild throughout many parts of the United States. Two species, B. eisenii and B. monnieri, are often found growing in rice fields and are treated as weeds.
Bacopa plants are found all over the world, from India and southeast Asia to the Americas. In the United States, it is primarily found in the southeastern part of the country, as this plant requires warm temperatures to grow and thrive. It is also found in Mexico, Central and parts of South America, according to the Institute for Regional Conservation.
Bacopa plants are moisture-loving and are often found near bodies of water. They have round, succulent green leaves and small white, purple or pink flowers. These perennials spread on runners, forming a thick mat of vegetation on wet riverbanks, boggy ponds, and other consistently wet landscapes. They average 2 to 4 inches in height, with a spread of around 4 feet. When the leaves or stems are crushed, they give off a pleasant, lemony smell.
The water-hyssop will grow in just about any type of soil, including hard clay soils, if the soil is moist enough. Bacopa plants will also grow (and float) on the surface of shallow water, as long as the roots are anchored nearby or under the water. These plants thrive in full sunlight and can crowd out desirable water plants, such as the water hyacinth. If growing in a container, make sure the soil is continually wet.
Problems and Benefits
Bacopa plants are considered to be invasive in some states. They can interfere with water crops or cover the surface of a body of water, blocking out the sunlight and cutting off the oxygen to fish and other aquatic plants and animals. Still, they are attractive in hanging baskets and attract butterflies. B. monnieri is used in India as an herb to help memory problems and as an antioxidant source, according to the Native Plants Hawaii website.