Dichotomosiphon A.Ernst, 1902

Holotype species: Dichotomosiphon tuberosus (A.Braun ex Kützing) A.Ernst

Original publication and holotype designation: Ernst, A. (1902). Siphoneen-Studien. Beihefte zum Botanischen Centralblatt 13: 115-148, pls 6-10.

Description: Thallus composed of prostrate, dichotomously branched siphons with frequent constrictions at each dichotomy and between the dichotomies. Siphons with numerous lens-shaped chloroplasts without pyrenoids, and numerous amyloplasts, containing granules of starch. Asexual reproduction by large tuberous akinetes, densely packed with starch, generally borne at the ends of rhizoid-like lateral branches, sometimes set off from the remainder of the thallus by a transverse cross-wall. Sexual reproduction oogamous with biflagellate male gametes, homothallic, with reproductive structures (antheridia and oogonia) borne on di-, tri-, or tetrachotomously branched end of a siphon, which are strongly curved; biflagellate male gametes released through an apical rupture of the antheridial wall; oogonia spherical, developing a small beak-like apical opening just before fertilization. Mature zygotes retained within the oogonium for a considerable time, packed with starch and surrounded by a smooth thick wall.

Information contributed by: Skaloud et al. (2018). The most recent alteration to this page was made on 2018-03-19 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 masculine.

Most recent taxonomic treatment adopted: Škaloud, P., Rindi, F., Boedeker, C. & Leliaert, F. (2018). Süßwasserflora von Mitteleuropa. Freshwater flora of central Europe: Chlorophyta V: Ulvophyceae. Vol. 13 pp. [i]-vii, [1]-288, 182 figures. Berlin: Springer Spektrum.

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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Some of the descriptions included in AlgaeBase were originally from the unpublished Encyclopedia of Algal Genera, organised in the 1990s by Dr Bruce Parker on behalf of the Phycological Society of America (PSA) and intended to be published in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=42972

Citing AlgaeBase
Cite this record as:
M.D. Guiry in Guiry, M.D. & Guiry, G.M. 19 March 2018. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org; searched on 22 November 2024