Cryptocoryne tonkinensis

Cryptocoryne tonkinensis is a slender and elegant species from Vietnam and southern China, one of the more northerly-distributed Cryptocoryne. Its very long, narrow, ribbon-like leaves are among the most grass-like of any Cryptocoryne species, creating a flowing, naturalistic background element in the aquarium. Leaves are dark green and can reach 30–40 cm in good conditions, producing a graceful, swaying effect in light current. It tolerates a broader range of temperatures than many tropical Cryptocoryne, reflecting its more temperate natural range. A striking and unusual species that provides a distinctive fine-textured contrast in the planted aquarium.

Light: Low to moderate; tolerates shade and varying photoperiods. CO2: Not required; manages well in low-tech conditions without CO2 injection. Fertilisation: Root tabs in substrate; light liquid feeding supports steady growth. Placement: Background; long, flowing leaves best appreciated in larger aquariums. Propagation: Runners from the rhizome; separate established daughter plants once rooted.