Origins of the Name Sea Kelp:

Kelps are large seaweeds (algae) belonging to the brown algae (Phaeophyceae) in the order Laminariales. There are about 30 different genera

Kelps grow in underwater "forests" (kelp forests) in shallow oceans. The organisms require nutrient-rich water with temperatures between 6 to 14 degree celsius. They are known for their high growth rate — the genera Macrocystis and Nereocystis can grow as fast as half a meter a day, ultimately reaching 30 to 80 m.

Through the 19th century, the word "kelp" was closely associated with seaweeds that could be burned to obtain soda ash (primarily sodium carbonate). The seaweeds used included species from both the orders Laminariales and Fucales. The word "kelp" was also used directly to refer to these processed ashes.