• Category
  • Length Range
    25-70 µm
  • Width Range
    3-5 µm
  • Striae in 10 µm
    Striae not visible to only faintly visible



Valves are linear with cuneate to subrostrate apices. The keel is strongly excentric, with fibulae numbering 6-8 in 10 µm. Striae faintly visible to unresolvable.

Inspection of the holotype slide, and other slides from the type locality, have revealed specimens as small as 25 µm in length. Note that the original description documented a range of 50-75 µm in length (Sovereign 1958, p. 131).

Found throughout the Pacific NW.


Original Description

  • Author
    Sovereign 1958
  • Length Range
    50-75 µm
  • Width
    3.5-5.0 µm
  • Striae in 10µm
    Unresolvable in LM

Original Images

Sovereign 1958  Plate  Iv

Cite This Page

Kociolek, P. (2011). Nitzschia columbiana. In Diatoms of North America. Retrieved May 20, 2024, from https://diatoms.org/species/nitzschia_columbiana


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