Cryptocoryne undulata

Cryptocoryne undulata is a medium-sized Cryptocoryne species from Sri Lanka recognized for its moderately to strongly undulated leaf margins and variable leaf coloration that ranges from olive-green to brownish-green, with some forms showing a reddish-brown tint under stronger light. Leaves are broadly lance-shaped with a moderate wavy edge, giving the plant an attractive, flowing appearance without the extreme corrugation of C. balansae. It reaches 20–30 cm in height, placing it firmly in foreground to midground territory in most aquariums. Cryptocoryne undulata is highly regarded as a reliable, adaptable plant that performs well across an unusually broad range of water conditions. It tolerates pH variations from 5.5 to 8.0 with equanimity and adapts to both soft and moderately hard water without significant performance degradation. This tolerance makes it a popular choice for community tanks with diverse livestock requirements. Growth is moderate, with the plant establishing steadily and producing runners to form natural-looking clusters. Like all Cryptocorynes, it draws the bulk of its nutrition from the substrate and benefits from root tab supplementation. CO2 injection is not required for healthy growth but improves speed and lushness. Crypt melt is a known risk when the plant is moved to a new environment; however, C. undulata recovers reliably from its rhizome. Its combination of attractive, understated beauty and low demands makes it a staple of the planted aquarium hobby.

Planting Plant the rhizome at or just above the substrate surface in the foreground or midground area. Suitable for tanks from 30 liters upward. Root tabs placed 2–3 cm below the rhizome support strong growth in nutrient-poor substrates.

Lighting Very low to moderate light (10–30 µmol/m²/s PAR) is well tolerated. Reddish-brown tones develop under moderate light with adequate iron.

CO2 and Fertilization CO2 supplementation is optional but beneficial. Root tabs every 3–4 months are the primary fertilization strategy. Liquid fertilizer provides supplemental trace elements.

Water Conditions Maintain pH 5.5–8.0 and temperature 20–28°C. Broad tolerance for hardness and community tank water conditions.

Crypt Melt Management Leaf melt upon introduction is possible. Remove decaying leaves; new growth from the rhizome will follow in 2–4 weeks.

Propagation Detach and replant runner-generated daughter plants once they develop 3 or more leaves.

Common Issues Yellowing leaves in established plants indicate nutrient depletion at the roots — add new root tabs. Overfeeding the water column without adequate flow may cause algae on leaf surfaces.