Common Name: Great Water Plantain

General Information

Alisma plantago-aquatica is a herbaceous perennial water plant with tubers 10 - 35mm in diameter. The plant produces a clump of leaves 2 - 30cm long and flowering stems 15 - 50cm long[]. Plants growing in water typically exhibit lax, often narrow, foliage whereas plants growing on muddy margins exhibit erect foliage[].
The plant is sometimes harvested from the wild for local use as a food and a medicine. It is sometimes grown as an ornamental in ponds and bogs.
The plant can become a weed problem, especially in cultivated rice fields, and will self-sow aggressively in suitable settings[].

Known Hazards

The fresh leaves and roots are toxic but the toxic principal is destroyed by heat or by drying[, ].
Fresh leaves can cause skin irritations[].

Botanical References

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Range

Widespread in the temperate and subtropical regions of Europe, including Britain, Africa, Asia, Australia

Habitat

Marshes, ditches, damp ground; shallow water up to 15cm deep in pond margins and slow-moving streams[, , , ].

Properties

Weed Potential	Yes
Edibility Rating
Medicinal Rating
Habit	Perennial
Height	0.50 m
Pollinators	Flies
Cultivation Status	Ornamental, Wild

Cultivation Details

Alisma plantago-aquatica is a plant of the temperate to subtropical zones, where it is found at elevations up to 1,500 metres. It grows best in areas where annual daytime temperatures are within the range 8 - 18°c, but can tolerate 6 - 24°c[]. When dormant, the plant can survive temperatures down to about -35°c[]. It prefers a mean annual rainfall in the range 500 - 1,500mm, but tolerates 400 - 1,700mm[].
An easily grown plant, it succeeds in a sunny position or light shade, though flowering is best in full sun[, ]. Grows best in fertile soils, which can be heavy, succeeding in boggy ground or in shallow water up to 25cm deep[]. Prefers a pH in the range 5 - 7, tolerating 4.5 - 7.5 [].
Plants often self-sow aggressively when in a suitable position[, ].
The subspecies Alisma plantago-aquatica orientale. Sam. Is the form used medicinally in China[].
Plants are very attractive to slugs[].

Edible Uses

Root - cooked[, , , ]. Rich in starch[]. Caution is advised, the root is acrid if it is not dried or well cooked before use[, ].

Leaves and petioles - must be thoroughly cooked. They require long boiling and have a salty flavour[, ].

Medicinal

Great Water Plantain has a long history of use in traditional medicine and has gained many and varied medicinal applications including the alleged treatment of rabies, whence comes the common name 'Mad-Dog Weed'[].

The leaves are antibacterial, anticholesterolemic, diaphoretic, diuretic, hypoglycaemic and hypotensive[, , ]. They are used in the treatment of cystitis, dysentery, renal calculus, gravel etc[].
The fresh leaf is rubefacient[], and is used externally in the treatment of leprosy[] and is also applied locally to bruises and swellings[].

The whole plant is believed to promote conception[].

Dried stem bases eaten, or grated and taken with water in treating digestive disorders such as heartburn, cramps and stomach flu[].

The powdered seed is an astringent, it is used in cases of bleeding[]. The seed is also said to promote sterility[].

The root contains an essential oil and has a wide range of medicinal uses[, , ]. It is antibacterial, anticholesterolemic, diuretic and hypotensive[]. It is said to lower blood pressure, cholesterol and blood sugar levels[] whilst it also has an antibacterial action on Staphylococcus, Pneumococci and Mycobacterium[]. The root is used in the treatment of oliguria, oedema, nephritis, acute diarrhoea, cholesterolaemia and fatty liver[]. It has been thought of as a cure for rabies, though this has not been substantiated[].
The root is harvested before the plant comes into flower and is dried for later use[].

A homeopathic remedy is obtained from the fresh root[].

Other Uses

None known

Propagation

Seed - best sown in a cold frame as soon as it is ripe. Place the pot in about 3cm of water to keep the soil wet. Pot up the seedlings when large enough to handle and keep in the cold frame for the first winter, planting out in late spring.
Division in spring or autumn. Fairly easy, the divisions can be planted straight out into their permanent positions.