Australian Vallisneria

Australian Vallisneria is the large-scale background plant for tanks where standard vallisneria looks undersized. Vallisneria australis grows tall enough to reach the surface of a 60 cm deep aquarium, with bright green leaves that are wider than those of V. spiralis. It is sold under several trade names including V. americana var. gigantea, V. gigantea, and V. neotropicalis, none of which are correct — the species was described from Australian material by Jacobs and Les.

Like all vallisnerias, it spreads by runners. In a large tank a few plants can fill the entire background in four to six months if not contained. The runners travel across the substrate and send up new shoots every few centimetres, so the plant is best kept within a buried plastic pot in smaller setups. CO₂ is not needed and the plant thrives in both soft and moderately hard water.

It does not grow emersed — the leaves are fully aquatic — but it can survive in outdoor ponds in milder climates. The species comes from temperate to subtropical Australia, which means it tolerates a broad temperature range. For the aquarium, 18 to 28 °C with neutral to moderately alkaline pH gives the best growth.