• Category
  • Length Range
    47-140 µm
  • Width Range
    16-25 µm
  • Striae in 10 µm
    8-12 in the central portion of the valve, 12-14 at the headpole, 13-16 at the footpole



Valves are broadly trullate, with broadly rounded apices. Initial valves are unknown. The axial area is narrow, straight, forming a relatively small, irregularly rounded central area. A single stigma is present in the central area. The raphe is lateral, weakly undulate and with small external proximal ends. The raphe has highly recurved internal proximal ends. Striae are distinctly biseriate, with the areolae arranged alternately. From the central nodule to the head-pole striae are radiate. From the central nodule to the foot pole striae are radiate, become parallel and near the footpole become strongly radiate. Longitudinal lines are positioned approximately one-half the way between the axial area and margin. The apical pore fields are distinctly bi-lobed but reduced in size.

Distribution: To date this species has been confirmed from relatively unimpacted lakes and rivers in the Pacific Northwest.


This species confirmed in relatively unimpacted lakes and rivers of the Pacific Northwest. The images shown for this taxon are from the Metolius River, Oregon.

Original Description

  • Author
    Kociolek and Stoermer 1988

Cite This Page

Kociolek, P. (2011). Gomphoneis herculeana var. loweii. In Diatoms of North America. Retrieved July 17, 2024, from https://diatoms.org/species/gomphoneis_lowei


The 15 response plots show an environmental variable (x axis) against the relative abundance (y axis) of Gomphoneis herculeana var. loweii 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.