Pontederia lanceolata

Pontederia lanceolata is similar to Pontederia cordata. However, it develops a taller clump of lance-shaped leaves to produce a beautiful plant, stunning when planted alone. Its slender habit, its erect bright green leaves, its stems reaching up to 1 m (3 ft) or 1.2 m (4 ft) in height, and its flowering with azure-blue spikes in summer make it a majestic aquatic or semi-aquatic plant. Flowering if it benefits from warmth and sunlight, it is not invasive and is easy to grow.

Pontederia lanceolata belongs to the Pontederiaceae family. This species is native to the shallow shores of North America, from Nova Scotia to Florida. It is a deciduous perennial plant with an upright and spreading habit. It reaches up to 1.2 m (4 ft) in height with a spread of 50 to 60 cm (20 to 24 in), and it has a rapid growth rate. It blooms from June to autumn in dense spikes of 5 to 10 cm (2 to 4 in), resembling orchid flowers, composed of bell-shaped azure-blue to lavender flowers illuminated by yellow stamens. The flowering is attractive to bees and butterflies, and it is followed by ovoid, red, sticky fruits that are enjoyed by ducks. The shiny lance-shaped leaves, 12 cm (5 in) wide and 25 cm (10 in) long, remain a medium green throughout the season and may sometimes have brown spots. It has thick and creeping rhizomes. It has a good purifying value (purifying value of reeds divided by two)*.

Plant Pontederia lanceolata in rich soil, submerged from 0 to 30 cm (0 to 12 in), or in 35 x 35 cm (14 x 14 in) baskets, preferably in spring, by burying the rhizome 10 to 15 cm (4 to 6 in) deep in the mud or by immersing the baskets. The substrate should ideally be humus-rich and clayey or loamy-clayey. This plant does not have specific soil pH requirements and can tolerate slightly alkaline, neutral, or slightly acidic soil. It prefers full sun or partial shade. Removing faded flowers can promote the appearance of new floral spikes. Pontederia lanceolata is perfectly hardy and highly resistant to urban pollution. Pontederia lanceolata is ideal in a wild or garden pond, or for decorating a patio container. It can also be used for mass planting in flooded areas and bogs.

*Plants used for phytopurification, such as Pontederia lanceolata, are increasingly used in small private sewage treatment plants and also in the installation of natural swimming pools and eco-friendly pools. First and foremost, they provide oxygen to the bacteria on the roots. These bacteria convert organic matter into mineral matter and nutrients. Secondly, the plant absorbs nutrients and removes elements that need to be eliminated, such as nitrates, phosphates, and heavy metals. Pontederia lanceolata is particularly effective at absorbing phosphates.

The fruits of Pontederia lanceolata were formerly consumed fresh, roasted, or ground into powder.