Alisma lanceolatum

Alisma lanceolatum is an aquatic plant with lanceolate leaves. Instead of being cordate, the leaves are elongated and lance-shaped with a green-blue colour. It is a perennial aquatic plant, living at a depth of 20 to 25cm (8 to 10in), with leaves emerging above the water. Its root is bulbous. The flowering occurs in summer, in fairly discreet panicles of purple-pink flowers. This plant is both decorative and useful. It boasts purifying properties in ponds. It requires little maintenance. It is perfect for maintaining the edges of water points.

It is a perennial belonging to the Alismataceae family. Its rosette habit easily reaches 70cm (28in) in height when in bloom. Its deciduous foliage measures 30cm (12in), spreading over 40cm (16in). From June to August, it produces purple-pink flowers, about 1.5cm (1in) in diameter. The flowers open in the afternoon, along a highly branched triangular flower stalk that can reach up to 1m (3ft) in height. There are 3 green sepals and 6 stamens per flower. Its green-blue lanceolate-shaped leaves measure 15 to 30cm (6 to 12in) long. This plant has a fibrous root. It is hardy beyond -15°C (5°F).

Plant this plantain in heavy, muddy or humiferous, acidic or neutral soil, up to 20 to 25cm (8 to 10in) deep. It appreciates sunny exposures. It prefers water banks or marshy areas. It does not require any specific care. However, remove faded flower stalks to avoid spontaneous sowing.

The water plantain is used as a filtering plant for phyto-purification. The very light flower stalks are beautiful in dry bouquets. They remain decorative even in winter, adorned with their faded inflorescences. This cosmopolitan plant will naturally find its place on the edge of all water points.