Colorata Rotala

Rotala rotundifolia 'Colorata' entered the trade as Rotala sp. 'Colorata' and is treated as a form of Rotala rotundifolia, a species variable enough that several red tinged forms circulate under different names, including the plants wrongly sold as Rotala indica. What sets this one apart is how little light it needs to show colour: it turns reddish under moderate light, and develops a proper red under strong light.

Stems grow 20 to 80 cm tall and 2 to 5 cm wide, fine enough that a dense stand reads as a red curtain at the back of a tall tank, and short enough to use in the midground if it is trimmed hard. Growth is fast and difficulty is rated medium.

The optimum is 22 to 28 °C, and the tolerance is remarkable at 4 to 32, wide enough that the plant is also listed as suitable for outdoor ponds. pH runs 4.5 to 8 and carbonate hardness 0 to 14 dKH, with medium to high light and carbon dioxide at 20 to 40 mg/l. The exact native locality is unknown, likely tropical or subtropical Asia. Trim the tops and replant them to keep the stand dense.