Docidium

Docidium
	Docidium baculum
Scientific classification
Kingdom:	Plantae
Class:	Zygnematophyceae
Order:	Desmidiales
Family:	Desmidiaceae
Genus:	Docidium; Brébisson ex Ralfs, 1848
Type species
	Docidium baculum; Brébisson ex Ralfs
Species
	Docidium baculum Bréb. ex Ralfs, 1848; Docidium hexagonum (Borge) Willi Krieger; Docidium manubrium West & G.S.West; Docidium undulatum Bailey;

Docidium is a genus of algae belonging to the family Desmidiaceae. The species of this genus have a cosmopolitan distribution but are rare; they typically occur in acidic, oligotrophic waters.^[2]

The name Docidium comes from the Greek term δοκίδιον (dokídion, 'small beam'), referring to its shape.^[1]

Description

Docidium consists of elongate, cylindrical cells which are many times longer than broad, and are composed of two identical halves, termed semicells. The apices are truncate and are either smooth or ornamented along the margins. The cell wall is smooth, undulated or annulate and may be covered in pores. At the base of the semicell (near the center of the cell) there is a row of granules/crenations or "teeth". The chloroplast is axile, stellate in cross section, and has a row of several pyrenoids along its length. Sexual reproduction is unknown.^[3]

The genus is very similar to Pleurotaenium and Haplotaenium, from which it differs in having a row of teeth at the base of the semicells.^[3]

References

^ ^a ^b Krieger, W. (1935). "Die Desmidiaceen Europas mit Berücksichtigung der aussereuropäischen Arten". Dr. Rabenhorst's Kryptogamen-Flora von Deutschland, Österreich und der Schweiz. 13 (Abteilung 1, Teil 1, Lieferung 2). Leipzig: Akademische Verlagsgeselschaft M.B.H.: 225–375.
^ ^a ^b Guiry, M.D.; Guiry, G.M. "Docidium Brébisson ex Ralfs, 1848". AlgaeBase. University of Galway. Retrieved 2025-04-13.
^ ^a ^b Hall, John D.; McCourt, Richard M. (2014). "Chapter 9. Conjugating Green Algae Including Desmids". In Wehr, John D.; Sheath, Robert G.; Kociolek, J. Patrick (eds.). Freshwater Algae of North America: Ecology and Classification (2 ed.). Elsevier Inc. ISBN 978-0-12-385876-4.

[Krieger-1] Krieger, W. (1935). "Die Desmidiaceen Europas mit Berücksichtigung der aussereuropäischen Arten". Dr. Rabenhorst's Kryptogamen-Flora von Deutschland, Österreich und der Schweiz. 13 (Abteilung 1, Teil 1, Lieferung 2). Leipzig: Akademische Verlagsgeselschaft M.B.H.: 225–375.

[AlgaeBase-2] Guiry, M.D.; Guiry, G.M. "Docidium Brébisson ex Ralfs, 1848". AlgaeBase. University of Galway. Retrieved 2025-04-13.

[Hall2014-3] Hall, John D.; McCourt, Richard M. (2014). "Chapter 9. Conjugating Green Algae Including Desmids". In Wehr, John D.; Sheath, Robert G.; Kociolek, J. Patrick (eds.). Freshwater Algae of North America: Ecology and Classification (2 ed.). Elsevier Inc. ISBN 978-0-12-385876-4.

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