What native plant typically has leaf blades that can grow up to 40 inches wide?

The American lotus is the native plant that is noted for its impressive leaf blades, which can grow up to 40 inches wide. This plant is well-adapted to aquatic environments and thrives in water bodies such as ponds and lakes. Its large, round leaves are not only striking visually but also play a crucial role in providing shade and habitat for various aquatic organisms. The broad leaf blades also help in photosynthesis by capturing more sunlight, thus allowing the plant to thrive in its aquatic habitat.

In contrast, the other options present much smaller leaf sizes or different forms. Watermeal, for instance, is one of the smallest flowering plants with tiny, microscopic leaves. Spatterdock is characterized by its distinctive yellow flowers and has narrower leaves compared to the American lotus, while Giant duckweed, also with smaller leaf sizes, consists of floating plants that form mats on the water surface. Thus, the distinction in size and morphology clearly identifies the American lotus as the correct answer in this context.