Common Water-plantain

Common Water-plantain - Alisma plantago aquatica

Very common river-side plant with characteristic lanceolate-ovate leaves supported by a long upright stalk.

As well as roots, the underground portion consists of a short, swollen tuberiform stem, from which grows the basal rosette of semi-submerged leaves.

These are glossy and differ in size (the first to grow are the smallest and are elongated) with 5-7 well marked main veins and unbroken margin.

Between June and September, a long floral stalk grows from the centre of the rosette, bearing verticillate branches (in whorls like a rays sprouting from the nodes) tipped with little umbels of flowers.

The small, pinkish white flowers have three petals. It is pollinated by insects, especially Hover Flies (Syrphidae).

The Common Water-plantain prefers lentic and eutrophic habitats. It is a pioneer plant and rapidly colonises newly formed bodies of water (phytopurifying stations, paddy fields etc.).