• Category
  • Length Range
    22-33 µm
  • Width Range
    4.4-8.8 µm
  • Striae in 10 µm
    16 (middle) to 20 (ends)
  • Synonyms
    Stauroneis soodensis (Krasske) Cholnoky 1962, p. 47
    Dickieia soodensis (Krasske) E.Reichardt 1997, p. 314, figs 60-71
  • Reported As
    Stauroneis legleri (Hustedt 1959, p. 793, fig. 1138; Hustedt 1959, p. 418, figs 5-7)



Valves are linear-lanceolate to elliptic-lanceolate, with bluntly rounded apices. Valves are strongly arched transapically; there is no distinct interface between the valve face and the mantle. The axial area is narrow. The central area is a narrow, and often slightly diagonal, transverse fascia. The raphe is filiform and straight, with proximal ends weakly expanded and bent to one side. The distal raphe fissures are hooked in the same direction. Striae are weakly radiate at valve center to parallel at the apices. The central fascia has one or two short striae at the valve margin. Areolae are very fine and difficult to resolve in LM.

Frustules may occur with "Janus valves", two distinct morphologies within a single frustule. "Normal" valves are described above. Janus valves have a larger, more rounded central area than normal valves.


Staurophora soodensis has been recorded from White Lake in Sheridan County, Montana, and from the Powder River in Wyoming. In White Lake the pH measured 10.0 and specific conductance was 87000 µS/cm. Hustedt (1959) reported this species (as Stauroneis legleri) from a saline lake in the Austrian Alps.

Original Description

Linear, nach den gerundeten Enden leicht verschmälert. In Gürtelansicht oft leicht Achnanthes-ähnlich gebogen. Ohne Längsarea, Zentralarea zu einer Querbinde verbreitert. Lang 20 - 26 µm, breit 5 µm. Streifen 18 in 10 µm, an den Enden etwas enger (20), leicht strahlend. Die Zentralarea neigt zu leicht unsymmetrischer Ausbildung (oft einseitig breiter).

  • Basionym
    Navicula soodensis
  • Author
    Krasske 1927
  • Length Range
    20-26 µm
  • Width
    5 µm
  • Striae in 10µm
    18 at center valve, 20 near the ends

Original Images

Naviculasoodensis Origimag010
Naviculasoodensis Origdesc009

Citations & Links



Cite This Page

Bahls, L. (2012). Staurophora soodensis. In Diatoms of North America. Retrieved May 18, 2024, from https://diatoms.org/species/staurophora_soodensis


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