Brown algae, comprising the class Phaeophyceae, are a large group of multicellular algae, including many seaweeds located in colder waters within the Northern Hemisphere. Brown algae are the major seaweeds of the temperate and polar regions. They are dominant on rocky shores throughout cooler areas of the world. Most brown algae live in marine environments, where they play an important role both as food and as a potential habitat. For instance, Macrocystis, a kelp of the order Laminariales, may reach 60 m (200 ft) in length and forms prominent underwater kelp forests. Kelp forests like these contain a high level of biodiversity. Another example is Sargassum, which creates unique floating mats of seaweed in the tropical waters of the Sargasso Sea that serve as the habitats for many species. Many brown algae, such as members of the order Fucales, commonly grow along rocky seashores. Some members of the class, such as kelps, are used by humans as food.
Leathesia marina (Lyngbye) Decaisne, 1842, previously known as Leathesia difformis Areschoug, 1847, commonly known as the sea cauliflower the sea potato, and brown brains is a species of littoral brown algae in the class Phaeophyceae and the order Ectocarpales, which is commonly attached to other seaweeds and sometimes rocks. When young, the organism is solid but as it matures it becomes hollow and somewhat convoluted and has the appearance of a small leathery brown bag about the same size as a tennis ball. The texture is rubbery and the outer surface smooth.
Sporochnacaeae is the only family in the order Sporochnales in the brown algae. Member of this family are thread-like algae growing by means of an intercalary row of dome shaped cells at the base of the hairs.
Dictyotales is a large order in the brown algae containing the single family Dictyotaceae. Members of this order generally prefer warmer waters than other brown algae, and are prevalent in tropical and subtropical waters thanks to their many chemical defenses to ward off grazers. They display an isomorphic haplodiploid life cycle and are characterized by vegetative growth through a single apical cell. One genus in this order, Padina, is the only calcareous member of the brown algae.
Colpomenia is a genus of brown macroalgae in the family Scytosiphonaceae.
Myriotrichia is a genus of brown algae.
Tilopteridales is an order of brown algae with isomorphic alternation of generations.
Scytothamnales is an order of brown algae.
Choristocarpaceae is a family in the order Discosporangiales of the brown algae. The family contains a single genus, Choristocarpus. The species is mostly located in the cold waters of the Northern hemisphere. A type of seaweed, Choristocarpaceae attaches itself to rocky substrate in places that are near continental shelves and the shore. Due to the species having morphological similarity, they were classified in closer relation with D. mesarthrocarpum. But due to many other differing characteristics Choristocarpaceae were put into their own family with a single genus and a single species of brown algae.
Discosporangiales is an order of brown algae. It includes two families, Choristocarpaceae and Discosporangiaceae.
Ralfsiales is an order of crustose brown algae containing two families.
Himanthalia is a genus of brown algae. It is the only genus in the family Himanthaliaceae in the order Fucales. It includes two species: Himanthalia durvillei and Himanthalia elongata.
Ralfsiaceae is a family of brown algae in the order Ralfsiales.
Phyllariaceae is a family of brown algae in the order Tilopteridales.
Scytosiphonaceae is a family of brown algae in the order Ectocarpales.
Ectocarpaceae is a family of brown algae in the order Ectocarpales. It includes four genera, Ectocarpus, Kuckuckia, Pleurocladia, and Spongostema.
Acinetosporaceae is a family of brown algae in the order Ectocarpales.
Sporochnus elsieae is a marine brown algal species in the family Sporochnaceae, endemic to New Zealand. It was first described in 1960 by Victor Lindauer who gave it the specific epithet, elsieae, in honour of his wife, Elsie.
Fucophycidae is a subclass of Phaeophyceae which contains the most complex and evolved orders of Chromista algae. The members of this subclass have stalks with several morphological forms and distinct structures, characterized by an intercalary growth and a basic heteromorphic, sometimes secondarily iso- or sub-isomorphic life cycle.
Rosenvingea is a genus of brown algae first described by Frederik Børgesen in 1914.
