Algae

Algae are the most common plants under water. Algae are found in fresh water and in salt water. The larger (attached) algae (macro algae) are commonly called seaweed. Algae have no true stems, leaves or flowers. Bigger algae in most cases have some sort of root like structure (hold-fast). They hold the plant on hard rocky bottoms, but they are not roots, because they cannot absorb nutrients from the bottom. The whole plant absorbs water with nutrients. Some algae are held erect with gas-filled bladders. The 3 groups are red, brown and green algae. The red alga is the only one that can be found at greater depth, because they make use of blue and green light only. To reproduce many bigger plants release spores.