Cryptocoryne × willisii "Pigmea"

Geographical Origin and Habitat: Cryptocoryne × willisii 'Pigmea' is a dwarf cultivated selection derived from the natural hybrid Cryptocoryne × willisii, which is native to the riverbanks and wet forests of the central highlands of Sri Lanka. The type species develops in areas characterized by alternating wet and dry seasons, growing submerged along seasonal forest streams. The 'Pigmea' variety has been selected and propagated in cultivation for its extremely small size, ideal for reproducing miniature underwater landscapes.

Taxonomy & Genetics: It belongs to the Araceae family, genus Cryptocoryne. The taxonomic entity Cryptocoryne × willisii is considered a stable natural hybrid complex combining the genetic traits of related Sri Lankan species such as C. parva, C. beckettii, C. walkeri, and C. undulata. The 'Pigmea' cultivar genetically fixes the dwarfing characteristic, maintaining stable small leaves even in the presence of abundant nutrient availability in the soil.

Physical Structure: The plant exhibits a dense, creeping herbaceous rosette structure, with a maximum height that rarely exceeds 5-8 cm. The leaves are narrowly lanceolate, almost needle-like when compared to other congenerics, supported by short, leathery petioles arranged radially around a thin, branched rhizome. The root system, although proportioned to the small size of the rosette, forms a dense network of whitish, fibrous roots that easily penetrate sandy substrates.

Color & Texture: The leaves show a bright green coloration, sometimes with slight bronze hues along the edges or near the base of the petiole under medium lighting. The leaf blade has a waxy, smooth texture, with straight or barely wavy margins. The fine and uniform texture of the clump creates a pleasant visual softness, similar to that of a submerged lawn.

Lighting & CO2: Adapted to low to moderate lighting conditions. Under too intense light, the leaves tend to grow prostrate and close to the ground, while under weak light the petioles stretch slightly vertically. CO2 injection is not critical, but a controlled dosage (5-12 mg/L) promotes development by producing closer and healthier runners.

Nutrition & Substrate: Prefers a fine, fertile substrate, such as fine-grained aquasoil (powder) or sand enriched with specific root fertilizer tabs. The plant absorbs most of its nutrients through its root system. Liquid

Water Chemistry: Tolerant of chemical parameters, it prefers soft to medium-hard water, with an optimal pH between 6.0 and 7.5. The optimal water temperature ranges from 20°C to 28°C. Regular water changes contribute to overall stability by avoiding pH or conductivity swings.

Space Management & Placement: It is ideal for foreground placement in aquariums of any size, and is particularly suitable for nano-aquariums. Plant it in small groups, spacing individual rosettes 2 cm apart; over time it will propagate, covering empty spaces and forming a compact green carpet.

Pruning: Slow growth makes pruning almost non-existent. It is only recommended to remove individual damaged or yellowing outer leaves by carefully cutting them at the base of the rhizome with precision scissors to prevent them from rotting on the bottom.

Risks & Diseases: Shows good resistance to Cryptocoryne melt, but drastic changes in light or fertilizers can trigger leaf decay. Due to its slow development, leaves can be colonized by green spot algae if the phosphate-to-nitrate ratio is not balanced.