Alisma plantago-aquatica L.

Conservation

IUCN Red List Assessment (2021): LC.

Kew Species Profiles

General Description

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Common water-plantain is a semi-aquatic or aquatic plant that is unrelated to true plantains, which are members of the genus Plantago.

Alisma is the ancient Greek physician Dioscorides' name for a plantain-leaved plant. The specific epithet, plantago is from the Latin for the sole of a foot, referring to the flat leaves, and aquatica is from the Latin for 'living in water', referring to the plant's habitat.

There are two subspecies of common water-plantain: Alisma plantago-aquatica subspecies plantago-aquatica, which is the most common and widespread of the two, and A. plantago-aquatica subsp. orientale, which occurs only in Asia.

Species Profile

Geography and distribution

Common water-plantain is a widespread temperate species occurring across Eurasia and from North Africa to Tanzania. It is also considered to be native in parts of Australia.

It is widely cultivated and has been introduced and become naturalised in parts of North and South America, Australia and New Zealand.

Alisma plantago-aquatica subspecies orientale is native to eastern and central Asia.

Description

Overview: An aquatic or semi-aquatic perennial with a clumped habit, up to 1 m tall.

Leaves: Rosettes of grey-green, elliptic, ribbed leaves, rounded at the base, up to 30 cm long on long fleshy stems.

Flowers: Tall open panicles of white flowers, sometimes with a pink or pale lilac tinge, up to 15 mm in diameter. Petals and sepals are in threes; there are six stamens (male parts) and numerous (variable) stigmas/carpels (female parts).

Fruits: Made up of a cluster of numerous achenes (dry fruits containing one seed) up to 7 mm in diameter. The fruits are buoyant, allowing water-borne dispersal.

Seeds: Deep reddish-brown to light pink or yellow. Remaining viable in water for many years.

Flowering stems emerge from the centre of the leaf bases, and delicate white, pink or lilac flowers unfurl in the afternoon for only a few hours, before closing again at dusk. During this time, the flowers are pollinated by flies, which are attracted by small drops of nectar.

Uses

The rhizome (underground horizontal stem) is used as a diuretic, but prolonged use may cause gastroenteritis (inflammation of the stomach and intestines).

According to the Flora of Pakistan , the powdered root has been used as a cure for hydrophobia, and fresh leaves are used in homeopathy. The starch-rich rootstock is also eaten in some countries.

John Ruskin, the well-known Victorian art critic, believed that the curve of this plant's leaves was representative of 'divine proportion', and advocated the emulation of nature and natural forms such as this in architecture, as in the Gothic style.

Millennium Seed Bank: Seed storage

The Millennium Seed Bank Partnership aims to save plant life worldwide, focusing on plants under threat and those of most use in the future. Seeds are dried, packaged and stored at a sub-zero temperature in our seed bank vault.

12 collections of Alisma plantago-aquatica seeds are held in Kew's Millennium Seed Bank based at Wakehurst in West Sussex.

Cultivation

Common water-plantain makes a good marginal or emergent plant for a wildlife garden or around lakes or garden ponds. It performs best in full sun and can grow in any aspect, in an exposed or sheltered site. It can be planted in up to 30 cm of water.

It can be propagated from ripe seed, freshly sown, or by dividing the rhizomes in spring. It will reach full height within 2-5 years.

This species at Kew

Alisma plantago-aquatica was first recorded in cultivation at Kew in 1768. It was first recorded growing wild in its natural habitat in the Gardens in 1873.

In recent years, it has been found growing wild in the ditch alongside the towpath, in one spot beside the Lake, and in the Larch Pond in the Conservation Area. It has been planted near the Sir Joseph Banks Building and can also be seen in cultivation in the Aquatic Garden, next to the Grass Garden. It can also be found growing at Wakehurst, Kew's sister garden.

Dried specimens of Alisma plantago-aquatica are held in Kew's Herbarium, where they are available to researchers by appointment.

Specimens of root and tubers of common water-plantain, used in medicine, are held in Kew's Economic Botany Collection, where they are available to researchers by appointment.

Distribution

Australia, Tanzania

Ecology

Pond margins, ditches, canals, slow-flowing rivers, streams and marshes; in shallow water or fertile mud.

Conservation

Least Concern according to IUCN Red List criteria.

Hazards

Poisonous if ingested in large quantities.

Alismataceae, Susan Carter. Flora of Tropical East Africa. 1960

Morphology General Habit

Aquatic herb.

Morphology Leaves

Petiole (10–)15–30(–40) cm. long; leaf-blade ovate, (5–)10–15(–25) × (2.5-)5–7(–12) cm.; base rounded to subcordate; nerves 5–9, not all radiating from the apex of the petiole.

Morphology Reproductive morphology Inflorescences Peduncles

Peduncle (2–)6–10 dm. high.

Morphology Reproductive morphology Inflorescences

Inflorescence of about 6 whorls of branches and flowers; bracts membranous, lanceolate, those of the lowest whorl 1–2 × 0.5 cm., with several smaller bracteoles.

Morphology Reproductive morphology Flowers Pedicel

Pedicels up to 2 cm. long.

Morphology Reproductive morphology Flowers Calyx

Sepals ovate, 2 mm. long.

Morphology Reproductive morphology Flowers Corolla

Petals 4 mm. long, white, delicate.

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens 2 mm. long; anthers 0.75 mm. long, narrow; filaments attached above the base.

Morphology Reproductive morphology Flowers Gynoecium Carpels

Carpels ovate, compressed, less than 1 mm. long; style about 1 mm. long, erect or slightly curved.

Morphology Reproductive morphology Fruits

Achenes broadly ovate, with 2 or 3 ridges on the dorsal surface, pale brown to yellowish.

Figures

Fig. 3, p. 6.

Habitat

Marshes and river margins, usually growing in shallow water; 900–2280 m.

Distribution

temperate regions of Europe, Asia, Australia and Africaaccording to Samuelsson (Arkiv Bot. 24A, No. 7 (1932)) distribution in the North American continent is limited to subsp. brevipes (Greene) Sam., while subsp. orientale Sam. is found in eastern and central Asia K3 K4 T2 U2

IUCN Red List of Threatened Species https://www.iucnredlist.org/species/164129/84275593

Conservation

LC - least concern

J. R. Timberlake, E. S. Martins (2009). Flora Zambesiaca, Vol 12 (part 2). Royal Botanic Gardens, Kew

Type

Type Europe (LINN 473.1 holotype).

Morphology General Habit

Perennial aquatic herb

Morphology Roots

Roots thin, densely covering the rhizome

Morphology Leaves

Leaves with petiole 10–30(42) cm long; limb 6–15(20) 2–8(10) cm, ovate to oblong-lanceolate, rounded to subcordate at base, acute at apex, with 5–9 nerves, not all radiating from apex of petiole, the cross-veins dense, parallel, arising from the midnerve

Morphology Reproductive morphology Inflorescences

Inflorescence a much branched pyramidal panicle with about 6 whorls of branch, the lower compound, each whorl with 4–6 branch and flowers, the ultimate bearing 1–6(9) umbellate flowers; peduncle 35–50(100) cm high, terete; bract membranous, lanceolate, acuminate, those of the lowest whorl 10–20 mm long; bracteoles several, smaller

Morphology Reproductive morphology Flowers Pedicel

Pedicels 10–30 mm long, filiform

Morphology Reproductive morphology Flowers Calyx

Sepals c.2 mm long, ovate, green

Morphology Reproductive morphology Flowers Corolla

Petals c.4 mm long, obovate, white or pink

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens c.2 mm long; anther c.0.75 mm long, narrowly elliptic. Carpels c.20, ovate, laterally compressed; style c.1 mm long, erect or slightly curved; stigma papillose

Morphology Reproductive morphology Fruits

Achenes c.2 mm long, broadly ovate, 2–3-furrowed dorsally, pale brown or yellowish.

Distribution

Zimbabwe. Cosmopolitan; known from the temperate regions of Europe, Africa, Asia, Australia, North America and South America (Chile). In Africa from Morocco to Egypt and southwards via the East African highlands to Tanzania. Introduced in Angola (Huíla), Zimbabwe and South Africa.

Ecology

In wet soils or shallow water of marshes and river banks; 900–2280 m in tropical East Africa.

Conservation

Conservation notes Introduced species; not threatened.

Note

The seed are buoyant because of subepidermal air-tissue and may float for many months. They are eaten by birds and pass unharmed through the alimentary canal.

Use

Ornamental, medicine.