Palmeria Greville, 1865, nom. illeg.
Holotype species: Palmeria hardmaniana Greville
Currently accepted name for the type species: Palmerina hardmaniana (Greville) G.R.Hasle
Original publication and holotype designation: Greville, R.K. (1865). Descriptions of new genera and species of diatoms from Hongkong. Annals and Magazine of Natural History, Series 3 16(91): 1-7, pl. V.
Request PDFDescription: Cells in the form of a segment of a sphere. Plastids numerous, discoid, very small. Marine and planktonic, probably limited to the tropics; according to Simonsen (1974) it is neritic. Valve semi-circular, with a flat valve face and an extensive mantle on the convex side, which rises from the corners to the centre of the semi-circle; there is almost no mantle along the straight edge. Areolae loculate (as in Coscinodiscus), externally with a cluster of central pores surrounded by a hexagonal outer series; internally with simple round, rimmed foramina. The areolae radiate from a plain area in the centre of the valve face. Hyaline rays run from near the centre and terminate near the valve margin at rimoportulae. Around the arc of the convex side the rimoportulae are located on the curved junction between valve face and mantle; on the straight edge they lie near the margin itself. Macro-rimoportulae occur, replacing the smaller rimoportulae on each valve near the centre of the convex, dorsal side. The other rimoportulae are relatively simple and tube-like internally. The rimoportulae are further apart along the straight edge than elsewhere. Copulae not known.
The most recent alteration to this page was made on 2016-03-24 by M.D. Guiry.
Taxonomic status: This name is currently regarded as a synonym of Palmerina.
Most recent taxonomic treatment adopted: Hasle, G.R. (1996 '1995'). Nomenclatural notes on Palmerina nom. nov.: Pseudo-nitzschia turgiduloides sp. nov. Diatom Research 10(2): 357-358, no figs.
Comments: It is important to distinguish this 'hemi-discoid' diatom from the genus Hemidiscus. Palmeria is clearly associated with Coscinodiscus on account of its wall structure and the type of rimoportulae whereas Hemidiscus has a pseudonodule and at present is allied to Actinocyclus. Simonsen (1972) reinstated Palmeria as a separate genus and, as with Hemidiscus, this can only be justified at present on the single criterion of cell shape. We would agree with Simonsen that it is more practical to maintain Palmeria as a genus and not 'crowd the genus Coscinodiscus more than is necessary'. The 'tubular' type of rimoportula occurs in some Coscinodiscus spp. whereas the 'slit' type occurs in others, in which the more complex macro-rimoportulae are lacking.
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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=45949
Citing AlgaeBase
Cite this record as:
M.D. Guiry in Guiry, M.D. & Guiry, G.M. 24 March 2016. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org; searched on 21 November 2024
