Lucens

The plant sold in aquarium shops as Cryptocoryne lucens is not a separate species but one named variety of the Cryptocoryne x willisii complex, a group of natural hybrids from the central highlands of Sri Lanka. The trade name comes from the botanist De Wit's 1962 description; Flowgrow keeps the same plant under Cryptocoryne x willisii 'lucens', which is how it is treated here.

Among the willisii hybrids this is the narrow-leaved one, with long, lance-shaped green blades on short stems, and Flowgrow puts the complex at about 20 cm submersed. It spreads by runners and by small plantlets that form at the rosette. Water of 22 to 28 °C and a pH of 4.5 to 8 covers its range, and it does not demand CO₂: Flowgrow calls it as easy as Cryptocoryne wendtii.

Its narrow leaves build dense, grass-like patches in the foreground or midground, useful as a slower alternative to spreading carpet species. It takes a few weeks to adjust after planting, then settles into steady, unhurried growth.