Parrot Feather Watermilfoil

The feathery, finely divided leaves of Myriophyllum aquaticum grow in dense whorls around the stem, creating a texture that stands out against broader-leaved background plants. It is one of the few milfoils that produces conspicuous emersed growth — the stems that reach the surface develop a thicker, more rigid form with a greyish-green tint, which is why it is also called parrot feather.

This plant grows quickly and tolerates a wide range of conditions. Moderate light and occasional liquid fertiliser keep it dense and green. CO₂ is not needed but speeds growth noticeably. In the wild it has naturalised outside its native South America and is classified as invasive in several regions, including parts of Europe and North America, so it should never be released into natural waterways.

Propagation is simple: cut a stem at any point and re-plant the cutting into the substrate. The lower stem also produces side shoots if the top is trimmed, giving a bushier appearance. In open-top tanks, the emersed portion flowers with small inconspicuous blooms. The plant can grow quite tall in the submerged form, reaching 50 cm or more under strong light.