Which plant features wide, waxy, wavy leaves with a broad base extending around the stem?

The plant characterized by wide, waxy, wavy leaves with a broad base extending around the stem is clasping-leaf pondweed. This distinctive leaf structure allows the plant to effectively anchor itself in aquatic environments while providing a unique adaptation for nutrient absorption and photosynthesis. The broad base of the leaves that clasp around the stem is especially notable, and this morphology can help to distinguish clasping-leaf pondweed from other aquatic plants which may have narrower or differently shaped leaves.

In contrast, curly-leaf pondweed typically exhibits more slender, finely serrated leaves that have a unique curly form, while Eurasian watermilfoil has feathery, finely dissected leaves that grow in whorls. Southern naiad, on the other hand, displays long, slender leaves that are less broad and do not feature the clasping base characteristic of clasping-leaf pondweed. Therefore, the unique leaf structures of clasping-leaf pondweed set it apart from these other aquatic plants, confirming it as the correct choice based on the description provided.