Crinum Thaianum

Crinum thaianum is an aquatic plant endemic to the rivers of southern Thailand that grows from a large bulb. Its leaves are smooth-edged, 1–2 cm wide, dark green and ribbon-like; in the aquarium they easily exceed 1 meter and keep growing while lying along the surface. Its tough leaves stand up to many plant-eating fish. Its range is very small and is shrinking because of human activity along the rivers, so the species is threatened in the wild; choose nursery-grown plants rather than ones collected from the wild.

Bury the bulb so that its neck stays above the substrate. Its strong, long roots need a substrate at least 8 cm deep, supported with root tabs. It is suitable only for large, tall (at least 60 cm) aquariums.

• Light: Medium.
• CO₂: Not required, but it supports growth.
• Fertilizer: A root tab once a month.
• Cut overly long leaves that pile up on the surface at the base. Daughter bulbs that form next to the bulb can be separated for propagation.