Which group comprises the majority of aquatic plants, excluding algae?

Flowering plants, also known as angiosperms, make up the majority of aquatic plants when excluding algae. These plants possess flowers and produce seeds, which allows them to effectively reproduce and adapt in aquatic environments. Common examples of flowering aquatic plants include water lilies, cattails, and duckweeds.

This group is significant because they fulfill various ecological roles in aquatic ecosystems, such as providing habitat, stabilizing sediments, and contributing to the oxygenation of water through photosynthesis. Non-flowering plants do exist in aquatic environments, but they represent a smaller fraction compared to flowering plants. Ferns, while they are a type of non-flowering vascular plant, are relatively limited in number in aquatic habitats. Sediments, although important in providing a substrate for plant growth, do not comprise a group of plants. Thus, flowering plants distinctly dominate the category of aquatic plants.