Algae

Endosymbiotic Theory: the origins of mitochondria and plastids (e.g. chloroplasts), which are organelles of eukaryotic cells. According to this theory, these organelles originated as separate prokaryotic organisms which were taken inside the cell as endosymbionts. (wikipedia)

Red Algae is also called Rhodophyta: different types of this include porphyra, chondrus and corallina

Brown algae is also called Phayeophyta: some examples of this are Desmarestia, Alaria, Fucus, Laminaria, Postelsia, and Macrocystis

Green algae is also called Chlorophyta: some examples of this are sea lettuce (ulva), Spirogyra, and Caulerpa The Evolution of Seagrass from Algae:

1) Algae: Algae came first, it was the simplist but the oldest and aquatic.

2) Non Vascular land plants: This came second it includes mosses, Hornworts and liverworths, it is small and lives near water

3) vascular land plants: This came last when the plants moved into the water