Streblonema Derbès & Solier, 1851

Holotype species: Streblonema sphaericum (Derbès & Solier) Thuret

Description: The genus is characterized by its non-specialized thallus organization. The species belonging to this genus are uniseriate, branched plants without specialized structures except true hairs. Unilocular and plurilocular sporangia occur together in some species, but also species with either unilocular or plurilocular sporangia occur. Culture studies have shown that many well-known species have Streblonema-like microthalli, for example Myriotrichia clavaeformis (Pedersen 1978b) and Litosiphon pusillus (Pedersen 1981a) belonging to the Tilopteridales s.l. and Sphaerotrichia divaricata (Ajisaka and Umezaka 1978), Acrothrix pacifica (Ajisaka 1979) and Stilophora rhizodes (Peters and Müller 1986) belonging to the syntagmatic Ectocarpales (Chordariales by some authors). These microthalli may under certain environmental conditions be physically connected with macrothalli. Other combinations of environmental conditions may disconnect them from the macrothallus and they may be found as seemingly independent species. The possibility that they are gametophytes also exists and if they are dioecious they may in culture behave like an independent species due to the highly selective isolation technique used by algal cultivators. Finally it cannot be excluded that Streblonema-like plants have evolved by complete suppression of the macrothallus or sexual reproduction is altogether lost. It therefore seems obvious that Streblonema is a polyphyletic genus which has evolved along different evolutionary lines. The genus is also paraphyletic as it is based on symplesiomorphic traits (Pedersen 1984). With our present knowledge it is therefore impossible to place these plants systematically.

Information contributed by: P. M. Pedersen. The most recent alteration to this page was made on 2014-06-20 by M.D. Guiry.

Taxonomic status: This name is of an entity that is currently accepted taxonomically.

Gender: This genus name is currently treated as neuter.

Most recent taxonomic treatment adopted: Silberfeld, T., Rousseau, F. & Reviers, B. de (2014). An updated classification of brown algae (Ochrophyta, Phaeophyceae). Cryptogamie Algologie 35(2): 117-156, 1 fig., 1 table.

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Contributors
Some of the descriptions included in AlgaeBase were originally from the unpublished Encyclopedia of Algal Genera, organised in the 1990s by Dr Bruce Parker on behalf of the Phycological Society of America (PSA) and intended to be published in CD format. These AlgaeBase descriptions are now being continually updated, and each current contributor is identified above. The PSA and AlgaeBase warmly acknowledge the generosity of all past and present contributors and particularly the work of Dr Parker.

Descriptions of chrysophyte genera were subsequently published in J. Kristiansen & H.R. Preisig (eds.). 2001. Encyclopedia of Chrysophyte Genera. Bibliotheca Phycologica 110: 1-260.

Linking to this page: https://www.algaebase.org/search/genus/detail/?genus_id=32870

Citing AlgaeBase
Cite this record as:
M.D. Guiry in Guiry, M.D. & Guiry, G.M. 20 June 2014. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org; searched on 22 November 2024