• Category
  • Length Range
    8-15.5 µm
  • Width Range
    3.5-7 µm
  • Striae in 10 µm
    8.5 near the center increasing to 18 at the apices



Valves are cruciform, with a round to rhombic inflation and broadly rounded rostrate to slightly capitate apices. In girdle view, valves are rectangular and the central inflation is distinct. The axial area may be wide in the valve center, to relatively narrow. Striae are mostly restricted to the margins and never meet in the central area. The central striae are longer than distal striae. The central striae are parallel to slightly radiate and often appear wider at the margin than proximally. The distal striae are short and parallel. Striae are uniseriate, with round to elliptical areolae.

This species was described from Holocene lake sediments in Poland (Marciniak, 1982).


Original Description

  • Basionym
    Fragilaria pseudoconstruens
  • Author
    Marciniak 1982

Original Images

P Pseudoconstruens Orig Ill 4
P Pseudoconstruens Orig Des 2

Cite This Page

Smith, T. (2013). Pseudostaurosira pseudoconstruens. In Diatoms of North America. Retrieved April 21, 2024, from https://diatoms.org/species/pseudostaurosira_pseudoconstruens


The 15 response plots show an environmental variable (x axis) against the relative abundance (y axis) of Pseudostaurosira pseudoconstruens from all the stream reaches where it was present. Note that the relative abundance scale is the same on each plot. Explanation of each environmental variable and units are as follows:

ELEVATION = stream reach elevation (meters)
STRAHLER = distribution plot of the Strahler Stream Order
SLOPE = stream reach gradient (degrees)
W1_HALL = an index that is a measure of streamside (riparian) human activity that ranges from 0 - 10, with a value of 0 indicating of minimal disturbance to a value of 10 indicating severe disturbance.
PHSTVL = pH measured in a sealed syringe sample (pH units)
log_COND = log concentration of specific conductivity (µS/cm)
log_PTL = log concentration of total phosphorus (µg/L)
log_NO3 = log concentration of nitrate (µeq/L)
log_DOC = log concentration of dissolved organic carbon (mg/L)
log_SIO2 = log concentration of silicon (mg/L)
log_NA = log concentration of sodium (µeq/L)
log_HCO3 = log concentration of the bicarbonate ion (µeq/L)
EMBED = percent of the stream substrate that is embedded by sand and fine sediment
log_TURBIDITY = log of turbidity, a measure of cloudiness of water, in nephelometric turbidity units (NTU).
DISTOT = an index of total human disturbance in the watershed that ranges from 1 - 100, with a value of 0 indicating of minimal disturbance to a value of 100 indicating severe disturbance.