Vallisneria americana var. biwaensis

The Lake Biwa vallisneria is now listed as Vallisneria asiatica var. biwaensis; the name used here is a synonym dating from the time when it was regarded as a variety of V. americana.¹² It is endemic to Lake Biwa in Japan, where, according to earlier information from a nursery, it forms large stands in sunny shallow water.¹² Its leaves bear fine marginal teeth that are visible without a magnifying glass and crowd more closely towards the leaf tip; the blades themselves are only 3–5 mm wide and frequently twisted in a spiral.¹

It was brought from Lake Biwa to Germany in 1991.¹² It does best in medium-hard to hard water; as it needs more light than other vallisnerias, it belongs in a bright position.¹ Since it usually grows only about 20–40 cm tall, it may even be suitable for the foreground of larger tanks.¹²

1. Kasselmann, C. (2019): Aquarienpflanzen. 4th edition (German). - Ulmer Verlag, Stuttgart: p. 571.
2. Vallisneria asiatica var. biwaensis – Flowgrow aquatic plant database (accessed 5 October 2026)