Crinum americanum Florida Swamp Lily

Crinum americanum is native to the swamps, marshes, and slow streams of the southeastern United States, particularly Florida and the Gulf Coast states. It is one of the largest aquatic bulb plants available to hobbyists, producing long, arching, bright-green strap-shaped leaves from a substantial onion-like bulb and, when conditions allow, spectacular white spider-lily flowers with long, reflexed petals and prominent stamens that are among the most beautiful of any aquatic plant.

In the aquarium, C. americanum functions as a dramatic background plant. Its leaves can reach 50–100 cm in large setups, so it is best suited to very large aquariums of 200 litres or more, or to outdoor pond features in warm climates. It tolerates a wide range of water conditions including moderate hardness and slightly brackish conditions, and grows without CO2 supplementation.

For North American biotope aquariums featuring species from Florida and the Gulf Coast region — such as flagfish, sunfish, or killifish — this plant is an ideal and ecologically appropriate choice, providing both structural cover and a sense of authentic habitat.

Light: Medium; tolerates bright to moderate light; outdoor sunlight promotes the strongest growth and occasional flowering. CO2: Not required; establishes and grows vigorously without any supplementation. Fertilisation: Rich substrate or aquatic fertiliser tablets beside the bulb every 8–10 weeks. Placement: Background in large aquariums or marginal pond position; leaves need substantial vertical space. Propagation: Produces offset bulbs (pupae) at the base of the main bulb; separate and replant when well-rooted.