• Category
  • Length Range
    18-28 µm
  • Width Range
    5.8-7.7 µm
  • Striae in 10 µm



Valves are elliptic-lanceolate to rhombic-lanceolate with triundulate margins and short apiculate apices. A pseudoseptum is present at each apex. The axial area is very narrow and linear, becoming wider near the central area. The central stauros is narrow and linear. The raphe is filiform with straight and weakly inflated proximal ends. Striae are weakly radiate throughout. Areolae are closely spaced and number 26-30 in 10 µm.

Stauroneis smithii is one of the most widespread and easily identified species of Stauroneis in the United States.


As an ecological generalist, Stauroneis smithii is widely distributed in a variety of habitats under varied water quality conditions. It is seldom found in abundance.

Staurossmithii Chem 001
Credit: Montana Diatom Database
Abundance-weighted means of selected water quality variables measured concurrently with the collection of samples containing Stauroneis smithii.

Original Description

  • Author
    Grunow 1860

Cite This Page

Bahls, L. (2012). Stauroneis smithii. In Diatoms of North America. Retrieved April 16, 2024, from https://diatoms.org/species/stauroneis_smithii


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