Agardhia Meneghini, 1838

Holotype species: Millepora polymorpha Linnaeus

Publication details: Meneghini, 1838: 366

Currently accepted name for the type species: Phymatolithon calcareum (Pallas) W.H.Adey & D.L.McKibbin ex Woelkering & L.M.Irvine

Original publication and holotype designation: Meneghini, G. (1838). Cenni sulla organographia e fisiologia delle alghe. Nuovi Saggi della [Cesarea] Regia Accademia di Scienze, Lettere ed Arti di Padova 4: 325-388.

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Description: A description is not provided as this name is not currently in use.

Information kindly contributed by Wm. J. Woelkerling but may now be outdated.

Taxonomic status: This name is currently regarded as a synonym of Phymatolithon.

Comments: In addition to being a superfluous substitute name for Apora Gunnerus, Agardhia Meneghini (1838) is a later homonym of Agardhia S.F. Gray (1821) (a rejected name in favour of Mougeotia C. A. Agardh; see ICBN Appendix III A3), Agardhia A. Cabrera (1823) (a superfluous substitute name for Codium J. Stackhouse; see separate AlgaeBase entry), and Agardhia K.P.J. Sprengel (1824), a genus of flowering plants.

Seven generic names are based on Millepora polymorpha Linnaeus and thus are ultimately typified by the type of Millepora calcarea Pallas. Chronologically these are Apora Gunnerus (1768), Nullipora Lamarck (1801), Agardhina Nardo (1834), Agardhia Meneghini (1838), Juergensia Reichenbach (1841), Phymatolithon Foslie (1898) and Eleutherospora Heydrich (1900). Because Phymatolithon is a conserved name, it automatically takes precedence over the other six names, which must be rejected under ICBN Art. 14.4, irrespective of when they were validly published. Separate entries for each name are provided in AlgaeBase.

An account of the epitype specimen of Millepora calcarea Pallas, the correct name for Millepora polymorpha Linnaeus, is provided by Woelkerling & Irvine (1986, as Phymatolithon calcareum).

Changes in the ICBN necessitated an update (Spencer et al. 2009: 253) to the original typification (Woelkerling & Irvine 1986 58) of Millepora calcarea; the species is now lectotypified by an illustration (Ellis 1755, Tab. 27, Fig. C) cited in the protologue (Pallas 1766: 265) and epitypified by BM 000562555 (Algal Box Collection 1626) housed in the Natural History Museum , London. Further information is provided in the AlgaeBase entry for Phymatolithon.

Nomenclatural note
The ICBN rules cited below are those adopted by the Seventeenth International Botanical Congress, Vienna, Austria, July 2005 (McNeill et al. 2006).

The nomenclature associated with Agardhia Meneghini is rather complicated. The generic name Agardhia Meneghini (1838: 366) is accompanied by a description and thus is validly published (ICBN Art 41.2) even though Meneghini did not describe any new species or effect any new species name combinations within the genus. Meneghini did not designate a type species, but amongst the taxa he explicitly included in his genuswas Millepora polymorpha Linnaeus, the type of Apora Gunnerus (1768) is based. This renders Agardhia Meneghini a superfluous substitute namefor Apora Gunnerus (ICBN Art 52) and thus illegitimate, as noted by Woelkerling & Irvine (1986) and Irvine & Woelkerling (1986). Moreover, Agardhia Meneghini automatically becomes typified by the type of Apora (ICBN Art 7.5) and thus the two names are homotypic (see below).

Apora Gunnerus (1768)is a validly published but formally rejected name in favour of Phymatolithon Foslie (1898), which is conserved under ICBN Art. 14 (see ICBN Appendix VII for definition of a conserved name). Phymatolithon is listed in the Nomina Generica Conservanda (ICBN Appendix III, A9), and in accordance with ICBN Art. 14.4, Phymatolithon is conserved against all other generic names based on the same type, including Apora (which is explicitly listed opposite Phymatolithon in ICBN Appendix III) and Agardhia Meneghini.

Apora, Phymatolithon, and Agardhia Meneghini are all based on Millepora polymorpha Linnaeus (1767: 1285), a superfluous substitute name for Millepora calcarea Pallas (1766: 265) and thus illegitimate under ICBN Art. 52. In accordance with ICBN Art. 7.5, Millepora polymorpha is automatically typified by the type of M. calcarea, the name that ought to have been adopted under the rules. The end result is that the type of M. calcarea is also the type of M. polymorpha and thus typifies the generic names Apora, Phymatolithon,and Agardhia Meneghini.

The current correct name (see ICBN Appendix VII for definition) for M. calcarea is Phymatolithon calcareum (Pallas) Adey & McKibbin (1970: 100). Details are provided in Woelkerling & Irvine (1986) and Irvine & Woelkerling (1986); also see the AlgaeBase entries for Apora and Phymatolithon. - (20 July 2009) - M.D. Guiry

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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=50894

Citing AlgaeBase
Cite this record as:
M.D. Guiry in Guiry, M.D. & Guiry, G.M. 20 July 2009. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org; searched on 24 May 2025