Cryptocoryne zwartii

Cryptocoryne zwartii is a striking and relatively recently introduced Cryptocoryne from Borneo, named for its very dark, near-black-green, heavily bullate leaves that create a dramatic contrast with pale substrates and bright green companion plants. In optimal conditions — soft, slightly acidic water with good iron nutrition and moderate lighting — the dark colouration reaches its full intensity, producing a deeply impressive effect. Like other Bornean Cryptocoryne, it grows slowly and prefers stable conditions. Its exceptional ornamental qualities have quickly made it popular among aquarists who have had the opportunity to obtain it, and it is becoming increasingly sought after.

Light: Moderate; sufficient light to develop the deep near-black colouration is important. CO2: Optional; CO2 supplementation supports stronger growth and better colour development. Fertilisation: Iron-rich fertilisation essential for maintaining leaf pigmentation depth. Placement: Midground contrast plant; pairs dramatically with bright green or red species. Propagation: Slow runners; handle carefully and allow daughter plants to establish fully.