Kelp are large seaweed plants (algae), belonging to the brown algae and classified in the order Laminariales. There're about 30 different genera. Some species can be very long and form kelp forests. Despite their plant-like appearance, scientists group them not with the terrestrial plants (kingdom Plantae), but instead place them either in kingdom Protista or in kingdom Chromista. Kelp grows in underwater "forests" (kelp forests) in shallow oceans. It requires nutrient-rich water below about… (More on Kelp)