Free floating hydrophytes - found in still waters. Aquatic plants are secondarily adapted to the water. The flower portion of the plant is above water where it is able to transport sugar from the atmosphere down into the water while water is transported up to the flower portion of the plant. Examples of Aquatic Macrophytes are giant kelps and seaweeds Both ferns and angiosperms have aquatic forms. Ferns have 5 aquatic families, with 200 known species.
Angiosperms divide into monocot and dicot families.
There are 10 dicot families, with 300 species. The Water Lily, mangroves and Ceratophyllum are examples of aquatic dicots. Common monocots are Zoestra, Potamogeton, Pondweed, Ruppia, Lemna, Typha, and Naja. Juncus - rushes, have a hollow stem. There are different zonation patterns for fresh and saltwater plants.