• Category
  • Length Range
    11-20 µm
  • Width Range
    4-5 µm
  • Striae in 10 µm
  • Reported As
    Pinnularia microstauron (Krammer and Lange-Bertalot 1986)



Valves are linear to elliptic-lanceolate, with rostrate apices (in most, but not all, specimens). The axial area is lanceolate, widening into a large central area that reaches the valve margins. The raphe is straight, with proximal ends bent slightly to one side. Striae are radiate near the valve center and slightly convergent near the apices.


Original Description

  • Author
    Schönfelder ex Krammer 2000
  • Length Range
    22-37 µm
  • Width
    4.7-6.3 µm
  • Striae in 10µm

Original Images

Marchica Original032
P Saprophila Description031

Cite This Page

Potapova, M. (2012). Pinnularia marchica. In Diatoms of North America. Retrieved May 24, 2024, from https://diatoms.org/species/pinnularia_marchica


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