What is characteristic of rushes?

Rushes are characterized by having solid, round stems. This unique stem structure is one of the key distinguishing features of rushes, setting them apart from other aquatic plants, such as sedges, which typically have triangular stems, and grasses, which usually have hollow stems. The solid nature of the rush's stem enables it to withstand various environmental conditions commonly found in wetland habitats.

Rushes thrive in a variety of moisture conditions, not limited solely to stagnant water, which makes option C less accurate. Their flowering characteristics can also be plain rather than bright and colorful; hence not producing particularly showy flowers aligns with the key characteristics of rushes, differentiating them from more ornamental flora. Overall, understanding the specific attributes of rushes helps in correctly identifying them and managing them in aquatic ecosystems.