Acetabularia is a genus of green algae in the family Polyphysaceae. Typically found in subtropical waters, Acetabularia is a single-celled organism, but gigantic in size and complex in form, making it an excellent model organism for studying cell biology. In form, the mature Acetabularia resembles the round leaves of a nasturtium, is 4 to 10 centimetres tall and has three anatomical parts: a bottom rhizoid that resembles a set of short roots; a long stalk in the middle; and a top umbrella of branches that may fuse into a cap. Unlike other giant unicellular organisms, which are multinucleate, members of this genus possess a single nucleus located in the rhizoid, which allows the cell to regenerate completely if its cap is removed. The caps of two Acetabularia may also be exchanged, even from two different species. In addition, if a piece of the stem is removed, with no access to the nucleus in the rhizoid, this isolated stem piece will also grow a new cap.
Florideophyceae is a class of exclusively multicellular red algae. They were once thought to be the only algae to bear pit connections, but these have since been found in the filamentous stage of the Bangiaceae. They were also thought only to exhibit apical growth, but there are genera known to grow by intercalary growth. Most, but not all, genera have three phases to the life cycle. In the subclass Nemaliophycidae there are three orders, Balbianiales, Batrachospermales, and Thoreales, which lives exclusively in freshwater.
Carteria is a genus of green algae in the family Chlamydomonadaceae. Carteria are similar in morphology to the common genus Chlamydomonas and differ by having four, rather than two, flagella at the vegetative stage.
Crustomastix is a genus of green algae in the class Mamiellophyceae.
Picocystis is a monotypic genus of green algae, the sole species is Picocystis salinarum. It is placed within its own class, Picocystophyceae in the division Chlorophyta.
Conceptacles are specialized cavities of marine and freshwater algae that contain the reproductive organs. They are situated in the receptacle and open by a small ostiole. Conceptacles are present in Corallinaceae, and Hildenbrandiales, as well as the brown Fucales. In the Fucales there is no haploid phase in the reproductive cycle and therefore no alternation of generations. The thallus is a sporophyte. The diploid plants produce male (antheridia) and female (oogonia) gametangia by meiosis. The gametes are released into the surrounding water; after fusion, the zygote settles and begins growth.
Pediastrum duplex is a species of fresh water green algae in the genus Pediastrum. It is the type species of the genus Pediastrum.
Hildenbrandia is a genus of thalloid red alga comprising about 26 species. The slow-growing, non-mineralized thalli take a crustose form. Hildenbrandia reproduces by means of conceptacles and produces tetraspores.
Amphiroa is a genus of thalloid red algae under the family Corallinaceae.
Compsopogonales is an order of mostly fresh water red algae.
Sirodotia Kylin (1912) is a genus of freshwater red alga which was described by Kylin in 1912, and placed in the Batrachospermaceae family.
Christine Adair Maggs is a British phycologist. Formerly Executive Dean of the Faculty of Science & Technology at Bournemouth University, she was the first Chief Scientist of the Joint Nature Conservation Committee, retiring in 2022. She is now an independent non-executive Director of Ocean Harvest Technology https://oceanharvesttechnology.com/corporate-governance/board-of-directors/
Michael Dominic Richard Guiry, is an Irish botanist, who specialises in phycology (algae). See for example the articles. He is the founder and director of the algal database, AlgaeBase.
Timothy (Tim) John Entwisle, is an Australian botanist, much of whose research work is in phycology (algae). See for example the articles. He was awarded a Ph.D. from La Trobe University in 1986 for work on the taxonomy of Vaucheria.
Greta Albrecht Fryxell was a marine scientist known for her work on the biology and taxonomy of diatoms. In 1996, she was elected a fellow of the American Association for the Advancement of Science.
Linda Karen Medlin is a molecular biologist known for her work on diatoms. She is an elected member of the Norwegian Academy of Science and Letters.
Thoreales is an order of red algae belonging to the class Florideophyceae. The order consists only one family, ThoreaceaeHassall, 1845. The family of Thoreaceae was circumscribed by Arthur Hill Hassall in A history of the British freshwater algae, including descriptions of the Desmideae and Diatomaceae in 1845.
Kathleen "Kay" Margaret Cole was a Canadian phycologist, known as one of the world's leading experts in the cytology of marine algae. In 1998 the Canadian Botanical Society awarded her the George Lawson Medal for lifetime achievement.
Stolonophora brandegeei is a species of marine brown algae in the family Sargassaceae, and the only species presenty recognised in the genus Stolonophora.
Batrachospermum is a genus of red algae from the family Batrachospermaceae. Due to its complex biological life cycle, descriptions of the taxon typically focus on gametophytes, while sporophytes, i.e., carposporophytes, are filamentous structures growing on the gametophyte, on which they depend. Independently living sporophytes have sometimes been described as separate species within the genus Chantransia. Additionally, differences may occur in the descriptions of the genus due to variations in taxonomic approaches, as new taxonomic techniques, as with other algae, result in changes in the assignment of individual species to the genus Batrachospermum. The genus is cosmopolitan, and its representatives are found in freshwater environments, mainly rivers, and less frequently in standing waters. These plants have thalli in the form of gelatinous-coated filaments.
