Tonina fluviatilis

Tonina fluviatilis is the only species in its genus and forms dense mats in shallow, slow-flowing blackwater streams in Central America and northern South America. Its short, pointed leaves are arranged spirally around the stem, giving the plant a starry, soft, light green texture. It is popular in Dutch-style layouts and as an accent plant in the midground. Its demands are high: it does not live long in hard water or in an aquarium without CO₂.

• Plant the stems individually, 3 cm apart, in an acidic active substrate.
• Because it grows slowly, choose an open spot where it will not be shaded by fast-growing stem plants.
• Since long stems root from their nodes outside the substrate, planting top cuttings of about 5 cm gives better results.

• Water: Soft (KH 5 at most); a pH below 6.5 is ideal.
• Light: High; it melts if left in the shade.
• CO₂: Required (20–30 mg/l).
• Fertilizer: Iron and trace elements should be plentiful; nitrate and phosphate should not drop to zero.
• It is propagated by cutting the tops; keeping it in a separate aquarium with plants of similar needs makes things easier.