Indian marshweed

The finely divided leaves arranged in whorls around a thick stem give Limnophila indica a texture that is closer to a Cabomba than to the broader-leaved stem plants it shares the background with. It is a fast-growing marsh plant from tropical Asia and Africa, and in the aquarium it is as close to bulletproof as a stem plant gets.

It accepts a wide range of conditions: pH 5 to 8, soft to hard water, and temperatures from 25 to 28 °C. Growth slows notably below 22 °C. CO₂ injection is not required, but the difference in stem density and leaf size between injected and non-injected tanks is visible — CO₂ produces a fuller, bushier plant.

The stems rise quickly to 30 or 40 cm, so regular trimming keeps the lower parts from going bare. Each trimmed stem branches below the cut, and runners from the base fill space sideways. It works best in groups of several stems planted close together rather than as a solitary specimen.

It can also grow emersed on wet substrate, producing small purple flowers. Propagation is trivial — cut a stem, strip the lower leaves, and push it into the substrate. Roots form within days.