Willow-leaf Hygrophila

Geographical Origin and Habitat: Native to Southeast Asia. It grows along muddy riverbanks, rice paddies, and ditches in warm, humid tropical zones.

Taxonomy & Genetics: Member of the Acanthaceae family and Hygrophila genus. Characterized by straight, firm stems and narrow, elongated leaves resembling willow leaves.

Physical Structure: Features robust, erect stems that grow vertically and can easily break the water surface. Submerged leaves are narrow, lanceolate, and opposite.

Color & Texture: Bright green to olive green. Under intense light, the upper leaves can develop coppery or brownish hues.

Lighting & CO2: Medium to high light demand. High light prevents the bottom of the stem from losing leaves. CO2 is not required but promotes denser growth.

Nutrition & Substrate: Benefits from a nutrient-rich substrate but is a heavy water column feeder. Potassium dosing is vital; deficiency results in pinholes in older leaves.

Water Chemistry: Adaptable to soft and hard water. Keep temperature at 20-28°C, pH 6.0-7.5. Prefers clean water with routine maintenance.

Space Management & Placement: Best placed in the background of medium to large tanks due to its height (growing up to 40 cm) and fast growth rate.

Pruning: Cut the stems above a leaf node. This will induce the plant to develop two side shoots, creating a bushier appearance.

Risks & Diseases: Highly prone to potassium deficiency, which causes small holes to appear in the leaves, leading to leaf drop.