Echinodorus grandiflorus is one of the largest Echinodorus species, native to tropical South America from Venezuela south to Argentina, where it grows in swampy margins and the edges of slow rivers. In the aquarium, it produces very broad, heart-shaped to ovate leaves on long, stout petioles that can easily reach 60–70 cm in tanks with strong lighting and rich substrate nutrition. It is named for its large white flowers, which it produces prolifically when allowed to grow emersed.
Due to its size, E. grandiflorus is only suitable for large aquariums of 200 litres or more, where it serves as a dramatic background anchor or solitary centrepiece. It grows vigorously under high light and responds strongly to heavy fertilisation, producing leaf after leaf in rapid succession under ideal conditions. In lower light it will survive but grow more slowly and produce smaller leaves.
Outside the aquarium, E. grandiflorus is widely used as a marginal pond plant in tropical and subtropical regions, where it can reach over 1 metre emersed. Its sheer scale and lush, tropical appearance make it one of the most impressive plants in the Echinodorus genus.