Which plant appears as small, green floating objects that may or may not have roots?

Duckweed is characterized by its appearance as small, green floating objects on the surface of water bodies. These tiny, often oval-shaped plants can vary in size but typically measure only a few millimeters across. While some species of duckweed may produce roots that dangle beneath the water, it is not a requirement for all types, as some may simply float freely. This adaptation allows duckweed to thrive in various aquatic environments, contributing to its success as one of the smallest flowering plants in freshwater ecosystems.

In comparison, cattails are larger, emergent plants that typically grow at the water's edge and are not floating. Purple loosestrife, on the other hand, is a tall, perennial plant that can be found in wetlands but does not float; instead, it grows upright and can form dense stands. Waterlilies are well-known for their larger, rounded leaves that float on the surface, often with flowers, but they are also significantly larger than duckweed and are anchored to the bottom of the water body via roots.