Staurosira construensvar.binodis (Ehr.) Hamilton in Hamilton et al.
Length: 18

 Width: 4

Striae:15






























Collection 1545

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Authority information

For new variety combination, see Hamilton et al. (1992). For genera transfer see Williams and Round (1987).

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From E. F. Stoermer's collection 1417.

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  • The valves of this species are biundulate with constricted middle portions and protracted, rostrate to capitate ends (Stoermer and Yang 1969).
  • Synonyms (Patrick and Reimer 1966)
    Fragilaria binodis Ehrenberg, Mikrogeol., pl. 5(2), fig. 26; pl. 6(1), fig. 43; pl. 11, fig. 15. 1854.


    Fragilaria construens var. binodis(Ehr.) Grunow 1862.
  • Ecology
    This species is found in cool fresh water and can tolerate high conductivity(Patrick and Reimer 1966). Asymmetric specimens, with a stronger constriction on one side than the other, are most commonly found in eutrophic waters (see "Other Images" above) (Stoermer and Yang 1969).

    Size ranges and morphology

  • Length is 15-35 micrometers (Patrick and Reimer 1966).
  • Breadth is 3.5-8 micrometers (Patrick and Reimer 1966).
  • Striae range is 14-17 per 10 micrometers (Patrick and Reimer 1966).
  • The size range and ornamentation is similar to the nominate variety (Stoermer and Yang 1969).