Phylum: Ochrophyta (Brown Algae)
The taxonomy presented here follows AlgaeBase as at early August 2026. Doubtless many new species await discovery and formal description, and this may necessitate the erection of novel higher taxonomic ranks.
Class: Chrysophyceae
Order: Chromulinales
Family: Chromulinaceae
| Scientific Name & Authority | Common Name/s | Distribution (Habitat) | Status (Last Record) | Taxon Profile |
| Ochromonas triangulata Vysotskii (1887) | - | Lake Veysove, Ukraine | Rediscovered | Access |
Families: Chrysamoebaceae, Chrysocapsaceae, Chrysolepidomonadaceae, Dinobryaceae
—No subordinate taxa
Orders: Apoikiales, Chrysosaccales, Chrysosphaerales, Hibberdiales, Hydrurales, Ochromonadales, Paraphysomonadales, Phaeoplacales, Rhizochrysidales, Segregatospumellales, Synurales, Thallochrysidales
—No subordinate taxa
Class: Eustigmatophyceae
Order: Eustigmatales
Family: Eustigmataceae
| Scientific Name & Authority | Common Name/s | Distribution (Habitat) | Status (Last Record) | Taxon Profile |
| Pseudostaurastrum subglobosum (Pascher) Bourrelly (1952) | - | Czech Republic, Germany & Netherlands | Rediscovered | Access |
Families: Chlorobotryaceae, Gloeobotrydaceae, Monodopsidaceae, Neomonodontaceae
—No subordinate taxa
Orders: Goniochloridales
—No subordinate taxa
Class: Phaeophyceae
Order: Desmarestiales
Family: Desmarestiaceae
| Scientific Name & Authority | Common Name/s | Distribution (Habitat) | Status (Last Record) | Taxon Profile |
| Desmarestia tropica W.R.Taylor (1945) | Tropical acidweed | Floreana & Isabela, Galápagos Islands | Missing (1972) | Access |
Family: Arthrocladiaceae
—No subordinate taxa
Order: Dictyotales
Family: Dictyotaceae
| Scientific Name & Authority | Common Name/s | Distribution (Habitat) | Status (Last Record) | Taxon Profile |
| Dictyota galapagensis (Farlow) De Clerck (2006) | - | Galápagos Islands, Ecuador | Missing (1974) | Access |
| Spatoglossum schmittii W.R.Taylor (1945) | - | Galápagos Islands (Fernandina, Floreana, Isabela, San Cristóbal & Santa Cruz) | Missing (1978) | Access |
Family: Scoresbyellaceae
—No subordinate taxa
Order: Ectocarpales
Family: Chordariaceae
| Scientific Name & Authority | Common Name/s | Distribution (Habitat) | Status (Last Record) | Taxon Profile |
| Zosterocarpus abyssicola W.R.Taylor (1945) | - | Post Office Bay, Galapagos Islands | Missing (29 January 1934) | Access |
Families: Acinetosporaceae, Adenocystaceae, Ectocarpaceae, Myrionemataceae, Petrospongiaceae, Scytosiphonaceae
—No subordinate taxa
Order: Fucales
Family: Fucaceae
| Scientific Name & Authority | Common Name/s | Distribution (Habitat) | Status (Last Record) | Taxon Profile |
| Gongolaria montagnei (J.Agardh) Kuntze (1891) | - | Algeria | Rediscovered | Access |
Family: Sargassaceae
| Scientific Name & Authority | Common Name/s | Distribution (Habitat) | Status (Last Record) | Taxon Profile |
| Bifurcaria galapagensis (Piccone & Grunow) Womersley (1964) | Galápagos stringweed | Galápagos Islands | Missing (February 1983) | Access |
Families: Bifurcariopsidaceae, Durvillaeaceae, Himanthaliaceae, Hormosiraceae, Notheiaceae, Seirococcaceae, Xiphophoraceae
—No subordinate taxa
Order: Sporochnales
Family: Sporochnaceae
| Scientific Name & Authority | Common Name/s | Distribution (Habitat) | Status (Last Record) | Taxon Profile |
| Nereia lophocladia J.Agardh (1897) | - | New South Wales & Victoria, Australia | Rediscovered | Access |
Orders: Ascoseirales, Asterocladales, Chordales, Discosporangiales, Ishigeales, Laminariales, Nemodermatales, Onslowiales, Phaeosiphoniellales, Ralfsiales, Scytothamnales, Sphacelariales, Stschapoviales, Syringodermatales, Tilopteridales
—No subordinate taxa
Classes: Bolidophyceae, Chrysomeridophyceae, Chrysoparadoxophyceae, Dictyochophyceae, Olisthodiscophyceae, Pelagophyceae, Phaeothamniophyceae, Pinguiophyceae, Raphidophyceae, Schizocladiophyceae, Synchromophyceae, Xanthophyceae
—No subordinate taxa
Statistics
| Conservation status | Number of taxa (in percentage) |
| Extinct | 0 |
| Missing | 5 (55.55%) |
| Extinct in the Wild | 0 |
| Possibly Extinct in the Wild | 0 |
| Globally Rediscovered | 4 (44.45%) |
| Rediscovered in the Wild | 0 |
| Reintroduced | 0 |
| Uncertain status | 0 |
| Hypothetical | 0 |
| Total | 9 (100%) |
| Erroneously listed | 0 |
| Invalid | 0 |
| Grand total | 9 (100%) |