Myriophyllum tuberculatum [Tc]

Myriophyllum tuberculatum populates slow-flowing and stagnant waters in the Asian tropics. M. tuberculatum is rather difficult in cultivation. It needs intensive light with at least 0.8 watts per litre, and CO2 injection is indispensable. Nitrates and phosphates should be maintained on a good level (5 to 15 and 1 to 2 mg/l, respectively). None of these main nutrients should ever fall to zero, otherwise the plant growth will be stunted. M. tuberculatum needs more iron and trace nutrients than most other stem plants. Without sufficient micronutrients the stems of this species remain very dark and small, and if there is an extreme deficit, the formative tissue of the shoot tip dies off. Under favourable conditions, the leaf whorls of M. tuberculatum can grow to a maximum diameter of around 10 cm and attain a rusty red colour.

Under good conditions this milfoil grows quickly to the water surface, where it grows lots of lateral shoots and develops a bushy habit. This species is best trimmed by removing the old stem and re-planting the strong upper part, as the rooted lower part only sprouts new shoots relatively slowly. For propagation, just cut off a lateral shoot and re-plant into the substrate.