# Gigartinales

Gigartinales is a red algae order in the class Florideophyceae.
Gigartinales, like all Florideophyceae, are exclusively multicellular.
In the cell walls of the Gigartinales order (e.g. Chondrus crispus, Kappaphycus alvarezii, Gigartina skottsbergi), agars are replaced by another family of sulfated galactans, the carrageenans.
Comparatively few red algae have so far been studied in detail as regards their cell wall material. Investigations tend to focus on red algae species that contain large quantities of polysaccharides of commercial interest (eg, carrageenans and agars) and which are available in large quantities on the seashore. Therefore members of the Gigartinales have received the most attention. This order, including almost half of the florideophycidaean families, consists of some 100 genera and 700 species..
Most of the gigartinalean species contain two or more recognizable carrageenan types; it is unusual for a single carrageenan type to be attributed to a given alga.
The biological life cycle and alternation of genders in Gigartinales lead to significant variation in the chemistry of extracted carrageenans. Algal growth and aging, which are conditioned by environmental factors, have also an impact on the carrageenan chemical structure and yield.

## Systematics

* Family Acrotylaceae
** Genus Acrotylus
** Genus Amphiplexia
** Genus Antrocentrum
** Genus Binderella
** Genus Claviclonium
** Genus Hennedya
** Genus Ranavalona
** Genus Reinboldia
* Family Areschougiaceae
** Genus Anatheca
** Genus Areschougia
** Genus Axosiphon
** Genus Erythroclonium
** Genus Meristiella
** Genus Neoareschougia
** Genus Notophycus
** Genus Reticulobotrys
** Genus Rhabdonia
** Genus Thysanocladia
* Family Blinksiaceae
** Genus Blinksia
* Family Calosiphoniaceae
** Genus Bertholdia
** Genus Calosiphonia
** Genus Schmitzia
* Family Catenellopsidaceae
** Genus Catenellopsis
* Family Caulacanthaceae
** Genus Catenella
** Genus Catenellocolax
** Genus Caulacanthus
** Genus Feldmannophycus
** Genus Heringia
** Genus Montemaria
** Genus Sterrocladia
** Genus Taylorophycus
* Family Chondriellaceae
** Genus Chondriella
* Family Choreocolacaceae
** Genus Leachiella
* Family Corynocystaceae
** Genus Corynocystis
* Family Crossocarpaceae
** Genus Crossocarpus
** Genus Erythrophyllum
** Genus Ionia
** Genus Kallymeniopsis
** Genus Velatocarpus
* Family Cruoriaceae
** Genus Cruoria
** Genus Erythroclathrus
* Family Cubiculosporaceae
** Genus Cubiculosporum
* Family Cystocloniaceae [fr]
** Genus Acanthococcus
** Genus Austroclonium
** Genus Bifida
** Genus Calliblepharis [fr]
** Genus Craspedocarpus
** Genus Cystoclonium
** Genus Dictyopsis
** Genus Erythronaema
** Genus Fimbrifolium
** Genus Gloiophyllis
** Genus Hypnea
** Genus Hypneocolax
** Genus Leptophyllium
** Genus Peltasta
** Genus Rhodophyllis
** Genus Stictophyllum
** Genus Stictosporum
* Family Dicranemataceae
** Genus Dicranema
** Genus Pinnatiphycus
** Genus Reptataxis
** Genus Tenaciphyllum
** Genus Tylotus
* Family Dumontiaceae
** Genus Andersoniella
** Genus Borrichius
** Genus Constantinea
** Genus Cryptosiphonia
** Genus Dasyphloea
** Genus Dilsea
** Genus Dudresnaya
** Genus Dumontia
** Genus Farlowia
** Genus Gibsmithia
** Genus Hyalosiphonia
** Genus Kraftia
** Genus Leptocladia
** Genus Litharthron
** Genus Masudaphycus
** Genus Neodilsea
** Genus Orculifilum
** Genus Pikea
** Genus Rhodopeltis
** Genus Thuretellopsis
** Genus Waernia
** Genus Weeksia
* Family Endocladiaceae
** Genus Acanthobolus
** Genus Endocladia
** Genus Gloiopeltis
* Family Furcellariaceae
** Genus Fastigiaria
** Genus Furcellaria
** Genus Halarachnion
** Genus Neurocaulon
** Genus Opuntiella
** Genus Turnerella
* Family Gainiaceae
** Genus Gainia
* Family Gigartinaceae
** Genus Chondracanthus
** Genus Chondroclonium
** Genus Chondrodictyon
** Genus Chondrus
** Genus Gigartina
** Genus Iridaea
** Genus Iridophycus
** Genus Iridophycus
** Genus Oncotylus
** Genus Ostiophyllum
** Genus Polymorpha
** Genus Psilophycus
** Genus Rhodoglossum
** Genus Sarcothalia
* Family Gloiosiphoniaceae
** Genus Baylesia
** Genus Capillaria
** Genus Gloeophycus
** Genus Gloiosiphonia
** Genus Peleophycus
** Genus Plagiospora
** Genus Rhododiscus
** Genus Thuretella
* Family Haemeschariaceae
** Genus Haemescharia
* Family Hypneaceae
* Family Kallymeniaceae
** Genus Austrophyllis
** Genus Austropugetia
** Genus Beringia
** Genus Callocolax
** Genus Callophyllis
** Genus Cirrulicarpus
** Genus Crossocarpus
** Genus Ectophora
** Genus Erythrophyllum
** Genus Euhymenia
** Genus Euthora
** Genus Glaphyrymenia
** Genus Hommersandia
** Genus Hormophora
** Genus Ionia
** Genus Kallymenia
** Genus Kallymeniopsis
** Genus Lecithites
** Genus Leniea
** Genus Meredithia
** Genus Nereoginkgo
** Genus Polycoelia
** Genus Psaromenia
** Genus Pugetia
** Genus Rhizopogonia
** Genus Rhodocladia
** Genus Salishia
** Genus Stauromenia
** Genus Thamnophyllis
** Genus Varimenia
** Genus Velatocarpus
* Family Mychodeaceae
** Genus Ectoclinium
** Genus Mychodea
* Family Mychodeophyllaceae
** Genus Mychodeophyllum
* Family Nizymeniaceae
** Genus Amylophora
** Genus Nizymenia
** Genus Stenocladia
* Family Phacelocarpaceae
** Genus Ctenodus
** Genus Euctenodus
** Genus Phacelocarpus
* Family Phyllophoraceae
** Genus Actinococcus
** Genus Ahnfeltiopsis
** Genus Archestenogramma
** Genus Besa
** Genus Ceratocolax
** Genus Coccotylus
** Genus Epiphylla
** Genus Erythrodermis
** Genus Gymnogongrus
** Genus Lukinia
** Genus Mastocarpus
** Genus Microgongrus
** Genus Ozophora
** Genus Pachycarpus
** Genus Petrocelis
** Genus Petroglossum
** Genus Phyllophora
** Genus Phyllotylus
** Genus Prolifera
** Genus Reingardia
** Genus Schottera
** Genus Stenogramma
* Family Polyidaceae
** Genus Polyides
* Family Rhizophyllidaceae
** Genus Chondrococcus
** Genus Contarinia
** Genus Nesophila
** Genus Ochtodes
** Genus Portieria
** Genus Rhizophyllis
* Family Rissoellaceae
** Genus Rissoella
* Family Schmiziellaceae
** Genus Schmitziella
* Family Solieriaceae
** Genus Agardhiella
** Genus Betaphycus
** Genus Eucheuma
** Genus Euryomma
** Genus Flahaultia
** Genus Gardneriella
** Genus Kappaphycus
** Genus Melanema
** Genus Meristotheca
** Genus Neoagardhiella
** Genus Placentophora
** Genus Sarcodiotheca
** Genus Sarconema
** Genus Solieria
** Genus Tikvahiella
** Genus Wurdemannia
* Family Sphaerococcaceae
** Genus Coronopifolia
** Genus Rhynchococcus
** Genus Sphaerococcus
* Family Tichocarpaceae
** Genus Tichocarpus