Ammannia gracilis. This colourful stem plant grows narrow, bright pink undulating leaves on a thick pink stem when ideal conditions are met. In less ideal conditions it will grow pale or even green foliage. Ammannia gracilis is relatively difficult to grow, requiring intense lighting, CO2 injection, water that is moderately soft and acidic with high levels of nitrate, phosphate and iron. In these conditions, this plant is fast growing and will require frequent trimming to encourage shorter, bushy growth for midground placement.