Sargassum polyphyllum
Sargassum polyphyllum is a species of brown (class Phaeophyceae) macroalgae or limu (seaweed) in the order Fucales. Description 
Sargassum polyphyllum, or limu kala, consists of thin, rough, wavy blades and a firm thallus. Its height can range anywhere from 4 to 70 centimeters. Sargassum polyphyllum is versatile and resilient enough to survive in areas such as harsh intertidal zones. Distribution and habitat 
Species of Sargassaceae can be found worldwide. However, Sargassum polyphyllum is endemic to the Hawaiian Archipelago. They can be found in intertidal pools and in depths of 75 meters below. Human use and cultural significance 
In Hawaiian culture, limu kala is involved in certain religious practices such as asking for forgiveness and certain hula. It is also used in food, as fish bait, and traditional medicine. References

Fucales
Taxa named by Jacob Georg Agardh