Hydrotriche

Hydrotriche hottoniiflora is a stem plant endemic to Madagascar, where it grows in both still pools and fast-flowing rivers, and every cultivated plant in the hobby descends from a single import to Europe in the late 1960s. Its bright green stems carry whorls of slender, needle-like leaves, giving it a soft, airy outline that no other stem quite matches, and it can reach about 50 cm.

It prefers soft, slightly acidic water and, while adaptable for a while, does best kept that way: Flowgrow suggests a pH of 5 to 7 and a wide temperature span of 21 to 34 °C, with a nutrient-rich substrate and a good supply of CO₂ for steady growth. It is a true aquatic plant rather than an emersed grower, and it flowers once the stems reach the surface.

Propagation is by cuttings, which root readily. Its fine-leaved texture works as a background mass in large tanks, where it reads well against red stems, and it responds to regular trimming by branching and thickening.