''Bacopa'' is a genus of 70–100

aquatic plant Aquatic plants are plants that have adapted to living in aquatic environments (saltwater or freshwater). They are also referred to as hydrophytes or macrophytes to distinguish them from algae and other microphytes. A macrophyte is a plant that ...

s belonging to the family

Plantaginaceae Plantaginaceae, the plantain family, is a large, diverse family of flowering plants in the order Lamiales that includes common flowers such as snapdragon and foxglove. It is unrelated to the banana-like fruit also called "plantain." In older cl ...

. It is commonly known as waterhyssop (or water hyssop, though this is more misleading as ''Bacopa'' is not very closely related to

hyssop ''Hyssopus officinalis'' or hyssop is a shrub in the Lamiaceae or mint family native to Southern Europe, the Middle East, and the region surrounding the Caspian Sea. Due to its purported properties as an antiseptic, cough reliever, and expecto ...

but simply has a somewhat similar appearance).

Description

They are annual or

perennial A perennial plant or simply perennial is a plant that lives more than two years. The term ('' per-'' + '' -ennial'', "through the years") is often used to differentiate a plant from shorter-lived annuals and biennials. The term is also wide ...

, with

decumbent This glossary of botanical terms is a list of definitions of terms and concepts relevant to botany and plants in general. Terms of plant morphology are included here as well as at the more specific Glossary of plant morphology and Glossary o ...

or erect stems. The

leaves A leaf (plural, : leaves) is any of the principal appendages of a vascular plant plant stem, stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", wh ...

are opposite or whorled, and

sessile Sessility, or sessile, may refer to: * Sessility (motility), organisms which are not able to move about * Sessility (botany), flowers or leaves that grow directly from the stem or peduncle of a plant * Sessility (medicine), tumors and polyps that ...

. The

leaf A leaf ( : leaves) is any of the principal appendages of a vascular plant stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, ste ...

blade is regular, round to linear, and the venation is palmate or pinnate. Its stems are hairy or smooth. The

flowers A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants (plants of the division Angiospermae). The biological function of a flower is to facilitate reproduction, usually by providing a mechani ...

are produced solitary or in pairs from leaf

axil A leaf ( : leaves) is any of the principal appendages of a vascular plant stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, st ...

s, usually radially symmetrical, with five

sepals A sepal () is a part of the flower of angiosperms (flowering plants). Usually green, sepals typically function as protection for the flower in bud, and often as support for the petals when in bloom., p. 106 The term ''sepalum'' was coined b ...

and five petals, and they are usually white, blue, or purple. Dispersal and propagation is by

seeds A seed is an embryonic plant enclosed in a protective outer covering, along with a food reserve. The formation of the seed is a part of the process of reproduction in seed plants, the spermatophytes, including the gymnosperm and angiosperm pl ...

and stem fragments. Crushed leaves have a distinctive 'lemon' scent. Bacopa myriophylloides

Habitat and range

''Bacopa'' species are found in tropical and subtropical regions of the world, particularly the

Americas The Americas, which are sometimes collectively called America, are a landmass comprising the totality of North and South America. The Americas make up most of the land in Earth's Western Hemisphere and comprise the New World. Along with th ...

. 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.

Uses

'' Bacopa monnieri'' is used in

Ayurvedic medicine Ayurveda () is an alternative medicine system with historical roots in the Indian subcontinent. The theory and practice of Ayurveda is pseudoscientific. Ayurveda is heavily practiced in India and Nepal, where around 80% of the population repor ...

. Preliminary clinical research found that the herb may improve cognition.

Cultivation

Some of these species are commonly used in freshwater

aquarium An aquarium (plural: ''aquariums'' or ''aquaria'') is a vivarium of any size having at least one transparent side in which aquatic plants or animals are kept and displayed. Fishkeepers use aquaria to keep fish, invertebrates, amphibians, aq ...

s and ponds in warmer climates. Most are easy to grow and will tolerate a wide range of conditions. '' B. monnieri'' will tolerate

brackish Brackish water, sometimes termed brack water, is water occurring in a natural environment that has more salinity than freshwater, but not as much as seawater. It may result from mixing seawater (salt water) and fresh water together, as in estuari ...

water up to 15 ppt, due to specialized adaptations that enable it to survive in saline environments.

Algal Algae (; singular alga ) is an informal term for a large and diverse group of photosynthetic eukaryotic organisms. It is a polyphyletic grouping that includes species from multiple distinct clades. Included organisms range from unicellular mic ...

infestation can be a problem in brighter lighting conditions.

Selected species

Formerly placed here

*'' Mecardonia procumbens'' (Mill.) Small (as ''B. procumbens'' (Mill.) Greenm.)

References

{{Taxonbar, from=Q1409203 Plantaginaceae Plantaginaceae genera Plants used in Ayurveda Freshwater plants Pantropical flora Taxa named by Jean Baptiste Christian Fusée-Aublet