• Category
  • Length Range
    36.2-54.3 µm
  • Width Range
    8.1-11.1 µm
  • Striae in 10 µm
    12-15 at valve center, 16-19 near the apices
  • Reported As
    Eunotia vanheurckii (Patrick & Reimer 1966, p. 210, plate 13, fig. 7)
    Eunotia vanheurckii (Camburn & Charles 2000, plate 15, figs. 16-18)
    Eunotia faba (Lange-Bertalot et al. 2011, p. 97, figs. 44: 1-23; 45: 1-6)



Valves are asymmetric to the apical axis and variably asymmetric to the transverse axis. Dorsal margins are moderately arched. Ventral margins are weakly concave. The apices are broadly rounded, with a deep notch on the ventral side. Helictoglossae are removed some distance from the apices. Terminal raphe fissures are very short at the junction of the valve face and mantle. Striae are radiate and very finely punctate. Forked, or short, costae occur along the dorsal margin in some specimens. Areolae are difficult to resolve in LM and number 30-35 in 10 µm.


Eunotia faba has been recorded from two lakes in the North Cascade Mountains of Washington. Patrick in Patrick and Reimer (1966) reports this taxon (as E. vanheurckii) from soft, somewhat dystrophic ponds, lakes and swamps in Maine and Pennsylvania. Camburn and Charles (2000) report this taxon (also as E. vanheurckii) from low-alkalinity lakes in the Adirondack Mountains of New York.

Nada  Lake
Credit: Ryan Davis, Adventurers and Scientists for Conservation.
Nada Lake, Chelan County, Washington: home of Eunotia faba.

Original Description

Cite This Page

Bahls, L. (2014). Eunotia faba. In Diatoms of North America. Retrieved May 29, 2024, from https://diatoms.org/species/eunotia_faba


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