Macrocystis integrifolia is a giant brown algae that inhabits the Pacific coast of North America, from Baja California to Alaska, as well as the coasts of southern seas, in South America, South Africa, Australia, and New Zealand. It lives from the intertidal zone to about 30 meters deep and can form underwater forests. Its individual specimens can reach lengths of 45 meters or more. The main commercial product obtained from this algae is alginate acid. M. integrofilia is the largest of all algae. The phase in which it is normally observed is that of the sporophyte, which is perennial and individuals subsist for many years.
As with other brown algae, they have structures that resemble those of plants. Its phyllodes ("leaves") are greenish-brown and can be more than half a meter long. Along the cauloid ("stem"), there are cysts, which are small air-filled vesicles that serve as floats. At its base, it has a grapnel fixation and stilettos (stem), from which the blades emerge towards the sea surface, in search of the sun and in constant movement, which helps in part to oxygenate the sea.
Alginate acid is used as a thickener and emulsifier in the production of processed foods, such as ice cream, desserts, sauces, baby foods, salad dressings, and many other uses. It is not usually consumed directly, preferring in general other species of brown algae for direct culinary use, such as Durvillaea antarctica (cochayuyo), consumed in Chile. For ceviche in Peru, the red algae Chondracanthus chamissoi is used.