Brown algae are a large group of multicellular algae comprising the class Phaeophyceae. They include many seaweeds located in colder waters of the Northern Hemisphere. Brown algae are the major seaweeds of the temperate and polar regions. Many brown algae, such as members of the order Fucales, commonly grow along rocky seashores. 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 that 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. Some members of the class, such as kelps, are used by humans as food.
The Fucales (fucoids) are an order in the brown algae. The list of families in the Fucales, as well as additional taxonomic information on algae, is publicly accessible at Algaebase.
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.
Ochrophytes, also known as heterokontophytes or stramenochromes, are a group of algae. They are the photosynthetic stramenopiles, a group of eukaryotes, organisms with a cell nucleus, characterized by the presence of two unequal flagella, one of which has tripartite hairs called mastigonemes. In particular, they are characterized by photosynthetic organelles or plastids enclosed by four membranes, with membrane-bound compartments called thylakoids organized in piles of three, chlorophyll a and c as their photosynthetic pigments, and additional pigments such as β-carotene and xanthophylls. Ochrophytes are one of the most diverse lineages of eukaryotes, containing ecologically important algae such as brown algae and diatoms. They are classified either as phylum Ochrophyta or Heterokontophyta, or as subphylum Ochrophytina within phylum Gyrista. Their plastids are of red algal origin.
Nemoderma is the only genus in the family Nemodermataceae and order Nemodermatales of the brown algae. The genus contains only a single species, Nemoderma tingitanum.
Ishigeales is an order of brown algae. It includes two families, Ishigeaceae and Petrodermataceae. The genus Diplura is also included, but not placed to family.
Tilopteridales is an order of brown algae with isomorphic alternation of generations.
Sphacelariales 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.
Ralfsiales is an order of crustose brown algae containing two families.
Camille François Sauvageau was a French botanist and phycologist.
Desmarestiaceae is a family of brown algae, one of two families in the order Desmarestiales. The family gets its name from the genus Desmarestia, which is named after the French zoologist Anselme Gaëtan Desmarest (1784-1838).
Desmarestia is a genus of brown algae found worldwide. It is also called acid weed, acidweed, oseille de mer, sea sorrel, ウルシグサ, stacheltang, mermaid's hair, landlady's wig, or gruagach. However, 'sea sorrel' can also specifically refer to Desmarestia viridis. Members of this genus can be either annual or perennial. Annual members of this genus store sulfuric acid in intracellular vacuoles. When exposed to air they release the acid, thereby destroying themselves and nearby seaweeds in the process. They are found in shallow intertidal zones.
Desmarestia tropica, sometimes called tropical acidweed, is a species of seaweed in the family Desmarestiaceae. It is critically endangered, possibly extinct, and one of only fifteen protists evaluated by IUCN. Endemic to the Galápagos Islands, the specific epithet tropica alludes to its tropical habitat, rare for members of Desmarestiales. The common name acidweed applies to members of the genus Desmarestia, generally characterized by fronds containing vacuoles of concentrated sulfuric acid, but it is unclear if this species also produces acid.
Zosterocarpus abyssicola is a species of brown algae endemic to the Galapagos islands.
Desmarestia anceps is a species of brown algae found in the Antarctic Peninsula.
Margaret Constance Helen Blackler (1902–1981) was a British phycologist, botanical collector and museum curator.
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.
