163,902 species and infraspecific names are in the database, 22,783 images, 63,102 bibliographic items, 484,277 distributional records.

Dilophus J.Agardh, 1882

Classification:
Empire Eukaryota
Kingdom Chromista
Phylum Ochrophyta
Class Phaeophyceae
Subclass Dictyotophycidae
Order Dictyotales
Family Dictyotaceae
Tribe Dictyoteae

Holotype species: Dilophus gunnianus J.Agardh

Currently accepted name for the type species: Dictyota gunniana (J.Agardh) I.Hörnig, R.Schnetter & Prud'homme

Original publication and holotype designation: Agardh, J.G. (1882). Till algernes systematik. Nya bidrag. (Andra afdelningen.). Lunds Universitets Års-Skrift, Afdelningen for Mathematik och Naturvetenskap 17(4): 1-134, 3 plates.
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Taxonomic status: currently regarded as a synonym of Dictyota.

Gender: This genus name is currently treated as masculine.

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.

Description: Thalli erect, attached by a rhizoidal holdfast or by robust, terete stolons, up to 40 cm long, dichotomous or becoming irregularly laterally branched, complanate, undulate or rugose, branches 1-28 mm broad, surface proliferations in some species numerous. Growth initiated by a single elliptical cell at each branch apex, transversely oriented to the thallus axis, slightly protruding to slightly depressed. Cortical cells monostromatic, 3-5 cells overlying each medullary cell in transverse section. Medullary cells in 1-7 layers in the central portion of the branch and 2-8 layers at the branch margin. Cortical cells with numerous discoid chloroplasts. Scattered hair tufts present. Sporangia solitary or in small groups, scattered on both thallus surfaces, down the central portion of each branch, or in the concavities of undulate or rugose thalli, or in elliptical sori formed around hair tufts. Sporangia ovoid to pyriform, 120-150 mm high when mature, with one or two basal stalk cells. Gametophytes dioecious. Oogonial sori (single oogonia in D. marginatus) scattered across both thallus surfaces leaving a sterile margin, or in the concavities of undulate or rugose thalli. Oogonia tightly packed in rows within sori (except D. marginatus), extending above the thallus surface with one stalk cell. Antheridial sori scattered across both thallus surfaces leaving a sterile margin, or in the concavities of undulate or rugose thalli, often becoming confluent, whitish, standing high above the thallus surface, bordered by 3-5 rows of elongate sterile cells. Antheridia with one stalk cell and many tiers of locules.

Information kindly contributed by J. A.. Philips and R. J. King but may now be outdated.

Comments: Southern Europe, Mediterranean Sea, Morocco, Australia, Japan, Pacific Coast of Mexico, Carribean Sea.

Numbers of names and species: There are 34 species names in the database at present.

Names: ('C' indicates a name that is accepted taxonomically; 'S' a homotypic or heterotypic synonym; 'U' indicates a name of uncertain taxonomic status, but which has been subjected to some verification nomenclaturally; 'P' indicates a preliminary AlgaeBase entry that has not been subjected to any kind of verification. For more information on a species click on it to activate a link to the Species database):

Click here to also show infraspecific names in the list below.

Verification of data
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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.

Created: 01 January 2001 by M.D. Guiry

Verified by: 23 February 2021 by M.D. Guiry

Linking to this page: http://www.algaebase.org/search/genus/detail/?genus_id=33775

Citing AlgaeBase
Please cite this record as:
M.D. Guiry in Guiry, M.D. & Guiry, G.M. 2021. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. http://www.algaebase.org; searched on 24 October 2021.

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