Which plant features oval to elliptical leaves and has jellylike slime on the underside?

The plant characterized by oval to elliptical leaves with jelly-like slime on the underside is Watershield. This distinctive feature sets it apart from other aquatic plants. The slime is a mucilaginous substance that can assist in protecting the plant from herbivory and may also help in retaining moisture, which is crucial for its survival in aquatic environments.

Watershield typically grows in shallow waters and is often found in ponds and slow-moving water bodies. Its leaves float on the surface, making it easily recognizable, especially by the unique texture and appearance of the underside. Other options like Small Pondweed, Widgeongrass, and American Lotus lack this specific slime characteristic, instead showcasing different leaf shapes and surface textures, which highlights why Watershield is the correct identification in this context.