Nesaea Crassicaulis

The plant long sold as Nesaea crassicaulis is now correctly placed in the genus Ammannia, following a 2013 transfer of several Lythraceae genera; the old name survives as a synonym and is used here only to point back to it. It is a stem plant of African and Madagascan swamps, rice paddies and slow rivulets that can reach 50 cm in the aquarium.

There is a persistent mix-up in the trade worth knowing: most of what is sold as N. crassicaulis is actually the similar Ammannia gracilis, which shows less intense red and a more yellowish-green hue. True A. crassicaulis keeps strong red tones under good light and is the more demanding of the two. It wants bright light, soft water with a pH of 5 to 7 and temperatures of 22 to 28 °C, and CO₂ injection keeps the stems dense and the colour strong.

Propagation is by cuttings, which root readily. It sits best as a red accent in the background or midground of a well-lit tank, where it contrasts with green stems, and it is used as a street plant in Dutch-style aquaria.