Plant atlas

Geographical Origin and Habitat: Hygrophila lacustris is native to North America, particularly the southeastern regions of the United States and parts of Mexico. In nature, it colonizes marshy wetlands, the clay margins of lakes, ponds, and slow-flowing watercourses. This warm-temperate geographical distribution gives it a great tolerance to seasonal temperature fluctuations and a marked adaptability to the submerged-emersed transition.

Taxonomy & Genetics: Belongs to the Acanthaceae family. At a taxonomic level, Hygrophila lacustris shares morphological affinities with other American species of the genus. It is sometimes confused with Asian narrow-leaved variants but maintains its own genetic signature related to its robust growth habit and leaf shape. There are no known widespread cultivars or artificial hybrids of this species.

Physical Structure: It develops thick and rigid vertical stems that grow straight up without bending easily. The leaves are arranged oppositely and are of a narrowly lanceolate or linear shape, with pointed tips. In the aquarium, the height of the plant can easily exceed 30-40 centimeters, making it an excellent choice for covering background equipment.

Color & Texture: The predominant color is an olive green or dark forest green, which under strong lighting and a good supply of nutrients (especially iron) can develop brown, coppery, or reddish hues on the upper leaves. The leaf texture is smooth, slightly matte, and the consistency is moderately rigid in the emersed form and more flexible in the submerged form.

Lighting & CO2: It is a robust plant that adapts well to a wide range of light intensities. It grows without problems under moderate light, but intense lighting promotes shorter internodes and the development of coppery tones. CO2 is not strictly necessary for growth, making it an excellent choice for low-tech aquariums, although it accelerates development if present.

Nutrition & Substrate: Hygrophila lacustris benefits from a fertile substrate containing clay and iron to support its root system. Liquid fertilization in the

Water Chemistry: Shows remarkable tolerance, adapting to pH levels between 6.0 and 7.5 and to both soft and moderately hard water. The ideal water temperature is between 18°C and 28°C. Regular water changes promote steady growth and keep the water clear, preventing the sedimentation of debris on the foliage.

Space Management & Placement: Optimal placement in the background of the layout or in the rear central area. Given the size of the leaves and the tendency to grow tall, it should be placed behind lower plants. It is advisable to plant the stems in small groups, spacing them to allow light to pass through.

Pruning: Pruning is done by cutting the top of the stems. The cut stem remaining in the substrate will quickly produce lateral branches from the node below the cut, thickening the group. The removed tops can be replanted directly to propagate the plant, rooting in a few days.

Risks & Diseases: It is a hardy species with few pathological risks. Potassium deficiency is the most common problem and manifests as small round holes on older leaves, leading to their drop. In poorly lit aquariums lacking fertilization, the stems can become bare in the lower part, losing aesthetic value.