Where do flowers of floating-leaf pondweed typically appear?

Floating-leaf pondweed, known scientifically as Potamogeton natans, produces its flowers on terminal spikes. This means that the flowering structures are positioned at the end of the stems that rise above the water surface. This adaptation allows for effective pollination by enabling the flowers to be accessible to flying pollinators such as insects.

The other options do not describe the typical flowering arrangement of floating-leaf pondweed. Flowers on underwater stems, for example, would not allow for the same level of pollinator access and thus would be less effective for reproduction. Similarly, flowers in separate floating clusters would not correspond to the observed growth pattern of this species. Lastly, flowers buried within thick mats of leaves would be even less accessible, hindering their potential to attract pollinators effectively. Hence, the best answer is that floating-leaf pondweed typically displays its flowers on terminal spikes.