Helanthium bolivianum 'Vesuvius'

Helanthium bolivianum 'Vesuvius', also known under the older name Echinodorus ‘Vesuvius’, is the first cultivar of the runner-forming sword plants or "chain swords" (Helanthium) to date. This aquatic plant with striking, twisted leaves is a mutant of Helanthium bolivianum 'Angustifolius' (formerly known as Echinodorus angustifolius) and was selected in the Oriental nursery (Singapore). It has been commercially available since 2006.
Under water, upright, linear, approximately 4 mm wide, pointed, tightly twisted leaves develop, which are arranged in a rosette. They have a fresh, medium to dark green colour and are somewhat transparent. The plant can grow to a height of around 40 cm. In our aquaria, however, it has so far only grown to a height of around 25 cm, which is much lower than the parent form H. bolivianum ‘Angustifolius’, which is reminiscent of a long and narrow-leaved Vallisneria. Like other Helanthiums, the plant forms long runner ‘chains’ with many young plants, but the growth of the runners is nowhere near as rapid as that of 'Angustifolius'.
The Vesuvius sword plant is usually sold in its terrestrial (emersed) form. It then has shorter, broader, less and irregularly twisted, often almost straight leaves and often also inflorescences. The typical long, narrow, tightly twisted submersed leaves only sprout under water. Unsightly emersed leaves can be removed later.

Helanthium bolivianum 'Vesuvius' is a relatively easy aquarium plant that tolerates a wide range of water values. Moderate light intensity is sufficient, but the location should be free and unshaded. The roots are best supported in a substrate that is not too coarse-grained, such as fine gravel, sand or aquasoil. A complete supply of macro and micronutrients via the substrate and/or the water column is recommended. The addition of CO₂ greatly promotes growth, but is not absolutely necessary if the pH value remains below 7.5. Temperatures between around 22 and 28 °C are ideal. If the plant thrives well, the runners creeping over the soil will not be long in coming and will enable it to reproduce abundantly. As a result, the population will quickly expand. If this is not desired, the runners can simply be removed.

The Vesuvius sword plant or corkscrew plant looks very decorative as a group or as a solitary plant in the aquarium midground, or in the background in smaller aquaria. With its upright, tightly twisted, narrow leaves, Helanthium bolivianum 'Vesuvius' is a real eye-catcher and contrasts with many other plants.