Sagittaria latifolia

The Sagittaria latifolia, also known as Broadleaf Arrowhead or Water Potato, is a perennial aquatic plant with large, lance-shaped leaves that are highly ornamental. It also produces white flowers along the stems in summer. Its filtering and dephosphating properties make it useful in lagoon systems or any wastewater treatment, such as phytoremediation. In addition to its practical uses, it also adds beauty to ponds. Plant it at a shallow depth, maximum 40 cm. If the conditions are favorable, it will slowly spread through stolons and can even become invasive in natural ponds.

The Sagittaria latifolia belongs to the Alismataceae family. It is a tuberous plant that grows up to 60 cm tall, and up to 1 m tall where it thrives. It is native to North and Central America and has naturalised in Europe and France. It can be found along lakes and rivers. It blooms in July-August. The flowers are arranged in whorls of three along the stem, with male flowers at the top and female flowers below. They are white with yellow stamens. This plant exhibits a unique characteristic: it has 3 types of leaves, known as foliar polymorphism. The submerged leaves form long ribbons up to 1.20 m long and can create true aquatic meadows. The floating emergent leaves are heart-shaped, and the upright leaves above the water are acute arrow-shaped. The underground stem produces numerous shoots that end in tubercles, which are used for propagation and are edible.

The Broadleaf Arrowhead has multiple uses. It is highly decorative and can be used to adorn ponds and aquatic containers on terraces. It is also suitable for filtering water along natural streams, in shallow stagnant waters, and in marshy gardens. It tolerates salinity and large water level fluctuations. To prevent it from becoming too invasive, it can be planted in submerged containers in ponds.