Species description

Care, breeding and tankmates

Plant profile

Placement

Midground

This species is ideally placed in midground of the aquarium. Its growth habit allows it to blend naturally with surrounding hardscape or other plants. When planted in small groups, it creates a cohesive and visually pleasing bush. Ensure it is not completely shaded by larger overhanging plants.

Botanical form

Rosette

Cryptocoryne cordata var. siamensis 'Rosanervig' features striking light pink and white leaf veins. Its rosette growth pattern is typical of the genus, creating a dense crown of foliage. The distinct leaf shape and coloration make it stand out in the aquarium. It is highly sought after for its unique venation.

Growth

Slow

The growth rate of Cryptocoryne cordata var. siamensis 'Rosanervig' is generally slow to moderate. Under lower light, it will grow slowly, but adding CO2 and moderate lighting can increase its pace. It steadily produces new leaves from its rosette once it has adapted to its environment. Patience is key, as it may take time to establish.

Substrate

High

The 'Rosanervig' variety of Cryptocoryne cordata var. siamensis requires a nutrient-rich substrate to fuel the production of its iconic pink-veined leaves. A deep bed of 2 to 3 inches of high-quality aquasoil is highly recommended to accommodate its demanding root system and provide a stable anchoring point. Consistently providing iron and essential trace minerals directly to the roots via substrate additives is necessary to maintain the striking white-to-pink variegation that defines this rare plant.

Column fertilization

Recommended

While primarily a root feeder, it still benefits from regular water column fertilization. Dosing a comprehensive liquid fertilizer ensures that micronutrients are available. Be careful not to overdose, as excessive nutrients in the water column can promote algae on its slow-growing leaves. A balanced approach is ideal.

Root fertilization

None

Root fertilization is crucial for the optimal development of Cryptocoryne cordata var. siamensis 'Rosanervig'. Providing a rich soil substrate or regularly inserting root tabs will yield the best results. Strong root feeding promotes larger, more robust leaves. It also makes the plant more resilient to environmental fluctuations.

Trimming

Occasional

Trimming should be done carefully by cutting old or decaying leaves near the base. Avoid pulling or uprooting the plant, as it has a delicate and extensive root system. Regular maintenance to remove dying leaves will keep the plant looking fresh and prevent rot. Only trim what is necessary.

Propagation

Rhizome division, Runners

Propagation is easily achieved through the natural production of runners. The mother plant will send out runners through the substrate, forming new plantlets. Once these plantlets have developed their own roots and a few leaves, they can be separated. You can carefully cut the runner and replant the new specimen.

Sensitivity

Moderate

Like many in its family, Cryptocoryne cordata var. siamensis 'Rosanervig' is prone to 'Crypt melt' when parameters suddenly change. Variations in temperature, lighting, or water chemistry can cause it to shed its leaves. However, the rhizome usually remains healthy. If melting occurs, leave the roots undisturbed and new leaves will soon emerge.

Layout role

Midground, Background

Its layout role is primarily for Unique focal points. The dense foliage and unique texture provide a natural transition between different zones of the aquascape. It is highly versatile and works well in both Nature Aquarium and Dutch styles. Its enduring presence makes it a reliable staple.