The species now placed in the Xanthophyceae were formerly included in the
Chlorophyceae. In 1899, Lüther created the group Heterokontae for green algae with unequal flagella. Pascher (1914) included the Heterokontae in the
Chrysophyta. In 1930, Allorge renamed the group as Xanthophyceae. The monadoid (unicellular flagellates) and also sometimes the amoeboid species have been included by some authors in the
Protozoa or
Protista, as order Heterochloridina (e.g., Doflein and Reichenow, 1927–1929), as class Xanthomonadina, with orders Heterochloridea and Rhizochloridea (e.g., Deflandre, 1956), as order Heterochlorida (e.g., Hall, 1953, Honigberg et al., 1964), as order Heteromonadida (e.g., Leedale, 1983), or as subclass Heterochloridia (e.g., Puytorac et al., 1987). These groups are called
ambiregnal protists, as names for these have been published under either or both of the ICZN and the ICN.
AlgaeBase (2020) Xanthophyceae have been divided into the following five orders in some classification systems: •
Dictyosphaeriopsis •
Groenlandiella •
Halosphaeropsis •
Pelagocystis •
Polyedrium •
Pseudopleurochloris •
Raphidosphaera •
Sphaerochloris •
Tiresias • Order
Botrydiales Schaffner 1922 • Family
Botrydiaceae Rabenhorst 1863 e.g.
Botrydium • Order
Mischococcales Fritsch 1927 • Family
Botrydiopsidaceae Hibberd 1980 e.g.
Botrydiopsis • Family
Botryochloridaceae Pascher 1938 e.g.
Ilsteria • Family
Centritractaceae Pascher 1937 e.g.
Centritractus • Family
Characiopsidaceae Pascher 1938 e.g.
Characiopsis,
Chlorothecium • Family
Chloropediaceae Pascher 1931 e.g.
Chloropedia • Family
Gloeobotrydaceae Pascher 1937 e.g.
Gloeobotrys • Family
Gloeopodiaceae Pascher 1938 e.g.
Gloeopodium • Family
Mischococcaceae Pascher 1912 e.g.
Mischococcus • Family
Ophiocytiaceae Lemmermann 1899 e.g.
Ophiocytium • Family
Pleurochloridaceae Pascher 1937 e.g.
Meringosphaera,
Pleurochloris • Family
Trypanochloridaceae Geitler ex Pascher 1938 e.g.
Trypanochloris • Order
Rhizochloridales Pascher 1925 • Family
Myxochloridaceae Pascher 1937 e.g.
Myxochloris • Family
Rhizochloridaceae Pascher 1925 e.g.
Rhizochloris • Family
Stipitococcaceae Pascher ex Smith 1933 e.g.
Stipitococcus • Order
Tribonematales Pascher 1939 • Family
Heterodendraceae Pascher 1939 e.g.
Heterodendron • Family
Heteropediaceae Hibberd 1982 e.g.
Heterococcus,
Heteropedia • Family
Neonemataceae Ettl 1977 e.g.
Neonema • Family
Tribonemataceae West 1904 e.g.
Tribonema • Family
Xanthonemataceae Silva 1980 e.g.
Xanthonema • Order
Vaucheriales Nägeli ex Bohlin 1901 • Family
Vaucheriaceae (Gray) Dumortier 1822 e.g.
Vaucheria Lüther (1899) Classification according to Lüther (1899): • Class Heterokontae • Order Chloromonadales • Order Confervales
Pascher (1912) Classification according to Pascher (1912): • Heterokontae • Heterochloridales • Heterocapsales • Heterococcales • Heterotrichales • Heterosiphonales
Fritsch (1935) Fritsch (1935) recognizes the following orders in the class Xanthophyceae: • Order Heterochloridales • Family Heterochloridaceae (e.g.,
Heterochloris) • Family Heterocapsaceae (e.g.,
Chlorogloea) • Family Mischococcaceae (e.g.,
Mischococcus) • Family Heterorhizidaceae (e.g.,
Rhizolekane) • Order Heterococcales • Family Halosphaeraceae (e.g.,
Halosphaera) • Family Myxochloridaceae (e.g.,
Myxochloris) • Family Chlorobotrydaceae(e.g.,
Chlorobotrys) • Family Chlorotheciaceae (e.g.,
Chlorothecium) • Family Ophiocytiaceae (e.g.,
Ophiocytium) • Order Heterotrichales • Family Tribonemataceae (e.g.,
Tribonema) • Family Heterocloniaceae (e.g.,
Heterodendron[?]) • Order Heterosiphonales • Family Botrydiaceae (e.g.,
Botrydium)
Smith (1938) In the classification of
Smith (1938), there are six orders in the class Xanthophyceae, placed in the division Chrysophyta: • Order
Heterochloridales (e.g.,
Chlorochromonas) • Order
Rhizochloridales (e.g.,
Chlorarachnion) • Order
Heterocapsales (e.g.,
Chlorosaccus) • Order
Heterotrichales (e.g.,
Tribonema) • Order
Heterococcales (e.g.,
Botrydiopsis) • Order
Heterosiphonales (e.g.,
Botrydium)
Pascher (1939) Pascher (1939) recognizes 6 classes in Heterokontae: • Class Heterochloridineae • Class Rhizochloridineae • Class Hetcrocapsineae • Class Heterococcincae • Class Hetcrotrichineae • Class Heterosiphonineae
Copeland (1956) Copeland (1956) treated the group as order Vaucheriacea: • Kingdom
Protoctista • Phylum
Phaeophyta • Class
Heterokonta • Order Vaucheriacea • Family Chlorosaccacea • Family Mischococcacea • Family Chlorotheciacea • Family Botryococcacea • Family Stipitococcacea • Family Chloramoebacea • Family Tribonematacea • Family Phyllosiphonacea
Ettl (1978), van den Hoek et al. (1995) In a classification presented by
van den Hoek, Mann and Jahns (1995), based on the
level of organization of the
thallus, there are seven orders: • Order
Chloramoebales (e.g.,
Chloromeson) - flagellate organisms • Order
Rhizochloridales (e.g.,
Rhizochloris, Myxochloris) - ameboid organisms • Order
Heterogloeales (e.g.,
Gloeochloris) - palmelloid (tetrasporal) organisms • Order
Mischococcales (e.g.,
Chloridella, Botrydiopsis, Characiopsis, Ophiocytium) - coccoid organisms • Order
Tribonematales (e.g.,
Tribonema, Heterococcus, Heterodendron) - filamentous organization • Order
Botrydiales (e.g.,
Botrydium) - siphonous organization; sexual reproduction
isogamous or anisogamous • Order
Vaucheriales (e.g.,
Vaucheria) - siphonous organization; sexual reproduction oogamous These are the same orders of the classification of Ettl (1978), an updated version of the classic work by Pascher (1939).
Ultrastructural and
molecular studies shows that the Mischococcales might be paraphyletic, and the Tribonematales and Botrydiales polyphyletic, and suggests two orders at most be used until the relationships within the division are sorted.
Maistro et al. (2009) Informal groups, according to Maistro et al. (2009): • Botrydiopsalean clade • Chlorellidialean clade • Tribonematalean clade • Vaucherialean clade Unicellular flagellates, amoeboid and palmelloid taxa were not included in this study.
Adl et al. (2005, 2012) According to Adl et al. (2005, 2012): • Tribonematales (genera
Botrydium, Bumilleriopsis, Characiopsis, Chloromeson, Heterococcus, Ophiocytium, Sphaerosorus, Tribonema, Xanthonema) • Vaucheriales (genus
Vaucheria) File:Stipitococcus capense.svg|
Stipitococcus capense (Rhizochloridales) File:British fresh-water algae, exclusive of Desmidieae and Diatomaceae (1882-1884) (20231360259).jpg|
Ophiocytium arbusculum (Mischococcales), formerly
Sciadium arbuscula File:British fresh-water algae, exclusive of Desmidieae and Diatomaceae (1882-1884) (19795451234).jpg|
Vaucheria sp. File:Album général des Cryptogames, Pl. 21.jpg|Other genera File:Alger, Botydium granulatum, Nordisk familjebok.png|
Botrydium granulatum (
Botrydiales) File:Vaucheria sp thallus 01.jpg|
Vaucheria sp. (Vaucheriales), thallus File:Vaucheria sp sexial reproductive organ01.jpg|
Vaucheria sp., sexual reproductive organs ==See also==