Pleurosigma

Belongs within: Bacillariophycidae.

Pleurosigma is a genus of diatoms with sigmoid frustules.

Characters (Crosby & Ferguson Wood 1959): Cells solitary, free; frustules in valve view sigmoid. Valves with central and terminal nodules; raphe usually sigmoid, often more so than valve margin; cell surface delicately marked by longitudinal or oblique and transverse striae.

<==Pleurosigma Smith 1852G75
    |--P. acuminatumG64
    |--P. aestuariiG75
    |--P. angulatum (Queckett) W. Sm. 1853 [=Navicula angulata Queckett 1848]CFW59
    |    |--P. a. var. angulatumW61b
    |    `--P. a. var. quadratum (W. Sm.) V.H. 1881 [=P. quadratum W. Sm. 1852]W61b
    |--P. arcuatumG64
    |--P. attenuatum [incl. P. agellus]G64
    |--P. balticum (Ehrenberg) W. Sm. 1853 [=Gyrosigma balticum (Ehrenberg) Cleve 1894]CFW59
    |    |--P. b. var. balticumM01
    |    `--‘Gyrosigma’ b. var. californicaM01
    |--P. carinatumG75 [=Donkinia carinataG64]
    |--P. compactum Grev. 1857CFW59 [=Donkinia compactaG64, Gyrosigma compactumCFW59; incl. Amphiprora ralfsiiG64]
    |--P. cuspidatum Cleve 1894 [=P. lanceolatum cuspidatum Cleve 1881]CFW59
    |--P. decorumG64
    |--P. delicatulum Smith 1953G63
    |--P. directum Grun. in Cleve & Grun. 1880W61a
    |--P. distortumG64
    |--P. elongatum W. Sm. 1853CFW59
    |--P. falcatumG64
    |--P. fasciola (Ehrenberg) W. Sm. 1853 [=Gyrosigma fasciola (Ehrenberg) Cleve 1894]CFW59
    |--P. formosum W. Sm. 1853CFW59
    |    |--P. f. var. formosumM01
    |    |--P. f. var. balearicaM01
    |    `--P. f. var. longissimaM01
    |--P. hippocampus (Ehrenberg) W. Sm. 1853 [=Navicula hippocampus Ehrenberg 1838]W61b
    |--P. intermedium Smith 1853G63 [=P. nubecula var. intermediaG75]
    |--P. kuetzingii Grun. 1860 [=Gyrosigma kuetzingii]CFW59
    |--P. lacustreG64
    |--P. lanceolatumG75
    |--P. latumM01
    |--P. littoraleG64
    |--P. macrumG64
    |--P. marinum Donk. 1858CFW59
    |--P. naviculaceum Brebisson 1867CFW59
    |--P. normanii [=P. affine var. normanii]G75
    |--P. nubecula W. Sm. 1853 [incl. P. intermedium Sm. 1853]CFW59
    |--P. obscurum Smith 1853W61a
    |--P. parkeri Harrison 1860W61b
    |--P. pelagicum Peragallo 1891G75
    |--P. planktonicumBM08
    |--P. prolongatumG64
    |--P. reticulatum Norman in Pritch. 1861 [=Donkinia reticulata]CFW59
    |--P. reversumG64
    |--P. rhombeumM01
    |--P. rigidum W. Sm. 1853W61b [incl. P. validum Shadb. 1854CFW59]
    |--P. rostratumG75
    |--P. salinarumTJ06
    |--P. speciosum Smith 1853W61a
    |--P. spenceriiG64
    |--P. strigilisG64
    |--P. strigosum Smith 1853 [=P. angulatum var. strigosa van Heurck 1880–1885]G63
    |--P. stuxbergiiB26
    |--P. tenuissimumG64
    |--P. transversale [=Gyrosigma transversale]G64
    `--P. wansbeckiiG64

*Type species of generic name indicated

References

[B26] Bigelow, H. B. 1926. Plankton of the offshore waters of the Gulf of Maine. Bulletin of the Bureau of Fisheries 40 (2): 1–509.

[BM08] Bruder, K., & L. K. Medlin. 2008. Morphological and molecular investigations of naviculoid diatoms. III. Hippodonta and Navicula s. s. Diatom Research 23 (2): 331–347.

[CFW59] Crosby, L. H., & E. J. Ferguson Wood. 1959. Studies on Australian and New Zealand diatoms. II.—Normally epontic and benthic genera. Transactions of the Royal Society of New Zealand 86 (1): 1–58, pls 1–9.

[G63] Giffen, M. H. 1963. Contributions to the diatom flora of South Africa. I. Diatoms of the estuaries of the eastern Cape Province. Hydrobiologia 21: 201–265.

[G75] Giffen, M. H. 1975. An account of the littoral diatoms from Langebaan, Saldanha Bay, Cape Province, South Africa. Botanica Marina 18: 71–95.

[G64] Gray, J. E. 1864. Handbook of British Water-weeds or Algae. R. Hardwicke: London.

[M01] Mereschkowsky, C. 1901. A list of Californian diatoms. Annals and Magazine of Natural History, series 7, 7: 292–300.

[TJ06] Taukulis, F. E., & J. John. 2006. Diatoms as ecological indicators in lakes and streams of varying salinity from the wheatbelt region of Western Australia. Journal of the Royal Society of Western Australia 89 (1): 17–25.

W61a] Wood, E. J. F. 1961a. Studies on Australian and New Zealand diatoms. IV.—Descriptions of further sedentary species. Transactions of the Royal Society of New Zealand 88 (4): 669–698.

[W61b] Wood, E. J. F. 1961b. Studies on Australian and New Zealand diatoms. V.—The Rawson Collection of recent diatoms. Transactions of the Royal Society of New Zealand 88 (4): 699–712.