Hydrothrix gardneri

Description

Hydrothrix gardneri is an annual aquatic plant native to eastern Brazil, where it thrives in stagnant to slow-flowing waters. It belongs to the Pontederiaceae family and resembles Eichhornia and Heteranthera despite its appearance. This plant grows submersed and has delicate, thread-like or hair-like leaves with an oval cross-section, measuring 2-4 cm long and ranging from light to dark green. The stems are thin, produce short lateral shoots resembling leaf whorls, and ramify readily. When cultivated in an aquarium, H. gardneri is relatively short-lived but can be maintained by sowing seeds. It produces submersed cleistogamous flowers on its nodes, which self-pollinate without opening. When stems float on the surface, the flowers open to reveal six yellow petals that fall off shortly after. After flowering, fruit pods appear, containing 18-40 seeds. The plant dies off once the fruit has ripened. Seeds can be collected and sown under water or will germinate spontaneously over time if not controlled. H. gardneri is a fast-growing plant with moderate demands, thriving in soft to moderately hard water with strong light intensity. Optimal temperatures range from 23-25°C (28°C maximum). Under unfavorable conditions, it may develop undulate leaves or long internodes with brown leaves. The plant can be propagated through top or lateral shoot cuttings, but this does not prevent flowering and seed production. Hydrothrix gardneri is a decorative stem plant with fine leaves, suitable for aquariums where it can be grouped with other plants of different textures and colors.