Hydrocotyle verticillata (Whorled Pennywort)

Hydrocotyle verticillata is a North and South American aquatic-to-marginal plant that produces perfectly round, peltate (umbrella-shaped) leaves arranged in characteristic whorls along thin creeping stems. In a paludarium it spreads across the waterline margins and onto moist substrate, bridging the water and land sections with its cheerful, coin-like leaves held above the surface on fine petioles. Tiny inconspicuous flowers appear in summer at the base of the petioles.

Its versatility is remarkable: it grows fully submerged as an aquarium plant, in the emergent waterline zone of paludariums, and even as a slow-spreading terrestrial groundcover on consistently moist substrate. It prefers nutrient-rich conditions and moderate to bright lighting for its best, most compact growth. It spreads horizontally by runners and is easy to propagate by cutting rooted segments.

Light: Medium to bright; 2,000–4,500 lux; low light causes long, leggy petioles and sparse growth. CO2/Humidity: No CO2 in emergent form; roots should remain at or below waterline. Fertilisation: Monthly dilute liquid fertiliser; benefits from iron and micronutrient supplementation. Placement: Plant at the waterline transition; allow runners to spread across both moist substrate and the water surface edge. Propagation: Cut rooted stem segments and replant; establishes quickly in warm conditions.