What is a key characteristic of floating plants?

A key characteristic of floating plants is that they rise and fall with water levels. This ability allows them to adapt to changing water conditions, such as fluctuations in the water level due to factors like rainfall or drought. By remaining buoyant, these plants can maximize their exposure to sunlight and absorb nutrients from the water while also preventing their leaves and flowers from being submerged at higher water levels.

In contrast, the other statements do not accurately describe floating plants. Many floating plants may have roots that are not anchored in the bottom soils, and while some can be partially submerged, they often rely on their buoyancy for stability and do not need to be completely underwater for survival. Furthermore, floating plants typically have both leaves and stems, which help to support their structure and facilitate photosynthesis.