Description
Medium-sized, fast growing, upright, rhizomatous deciduous perennial (H 70-110 cm, W 40-60 cm). Leaves narrow, sward-like (50-90 cm), upright or partly drooping, smooth, vivid green. Flowers in clusters on upright stems, large (7-10 cm), bright yellow. Flowering period: May-June. Suitable for always moist and marshy soils or shallow water.