• Category
  • Length Range
    40-64 µm
  • Width Range
    7.4-11.1 µm
  • Striae in 10 µm



Valves are lanceolate with gradually attenuated, narrowly rostrate to subcapitate apices. The axial area is about three times wider than the raphe and linear, widening slightly near the narrow stauros. Short striae are sometimes present in the stauros. The raphe is weakly lateral. Proximal raphe ends are nearly straight (deflected slightly to the primary side) and not expanded. Striae are parallel at the center, becoming radiate near the apices. Areolae are variably spaced and number 22-28 in 10 µm.


Stauroneis schroederi is very rare in the Northern Rockies. To date it has been found only in one lake and a small pond. The pH of the lake (Beeskove) is 7.4 and the specific conductance is 10 µS/cm. The pH of the pond (Bloody Dick #5) is 7.8 and the specific conductance is 41 µS/cm. The type locality of this taxon is Wilhelmtal in the Sudeten Mountains of Silesia, southwest Poland. Lange-Bertalot et al. (2003) reported this species from Sardinia.

59580024 0001
Credit: Loren Bahls
Bloody Dick Pond #5, Beaverhead County, Montana: home of Stauroneis schroederi.

Original Description

  • Author
    Hust. in A.Schmidt 1913

Original Images

Sschroederi Origimag1
Sschroederi Origimag2

Cite This Page

Bahls, L. (2011). Stauroneis schroederi. In Diatoms of North America. Retrieved July 19, 2024, from https://diatoms.org/species/stauroneis_schroederi


The 15 response plots show an environmental variable (x axis) against the relative abundance (y axis) of Stauroneis schroederi 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.