Hydrocotyle leucocephala (Emergent)

Hydrocotyle leucocephala, Brazilian Pennywort, is one of the most popular and fastest-growing aquarium stem plants, and its emergent form is equally vigorous. Above the waterline it produces noticeably larger, kidney-shaped leaves on longer petioles, and periodically bears small clusters of white flowers. The emergent form integrates the water and land zones in a paludarium with a lush, tropical waterside character reminiscent of South American gallery forests.

It is one of the easiest emergent plants to establish — stems simply grow upward from a submerged base and begin producing emergent growth naturally without any special encouragement. The rapid growth rate means it requires regular trimming to prevent it from dominating the waterline zone, but the trimmings propagate instantly by replanting. It is an excellent nutrient exporter in densely stocked paludariums.

Light: Medium to bright; 2,000–5,000 lux; strong light produces the most compact, attractive emergent growth. CO2/Humidity: No CO2 in emergent form; roots and lower stems should remain submerged or in saturated substrate. Fertilisation: Weekly dilute liquid fertiliser into the aquatic section; fast grower with correspondingly high nutrient needs. Placement: Plant in the substrate at the waterline; stems will grow upward and arch outward over the land section. Propagation: Cut stems with at least three nodes and replant in substrate; roots within days.