Algae are simple plants that lack roots, stems, leaves, flowers, seeds, and vascular tissue. They are mostly aquatic, but some terrestrial forms survive in dry conditions in a symbiotic relationship with fungi (see Lichen). Algae come in different forms such as single-cells, stringed-cells, and even seaweeds and giant kelps that can reach up to 80 m in length (see Seaweed). Despite their simplicity, algae are essential plants that produce about 80% of earth’s oxygen. Over two billion years ago, primitive algae released oxygen into the earth’s atmosphere, setting the stage for more complex life forms. As the first plants on earth, all higher plants evolved from algae. The world’s petroleum formed mainly from the remains of prehistoric algae.
Widespread in all aquatic habitats, including rivers, reservoirs, irrigation pools, and hot springs. Common in river valleys such as Wadi Mujib, Wadi Hidan, and Ma’in.