E. major is a medium- to large-sized rosulate plant that reaches a maximal height of 60 cm, with a rhizome and light green, translucent submersed leaves with a narrow oblanceolate form. The leaf blade reaches its widest point a little above the middle. The undulate margin and the long narrow lower part of the leaf blade with a round or truncated basis are its most striking characteristics. The first pair of longitudinal veins branches off the midrib near the middle of the leaf blade. The leaf tip is obtuse.
When cultivated in an aquarium, this plant does not form floating or emersed leaves, which is very probably crucial for its continuous popularity as aquarium plant.