• Category
  • Length Range
    33-63 µm
  • Width Range
    12-14 µm
  • Striae in 10 µm
    12-14 at the central portion of the valve, 14-15 at the poles



Valves are broadly lanceolate-clavate, with an apiculate headpole and rounded footpole. The axial area is narrow and expanded in the middle of the valve to form a rounded central area. A single stigma is present. Striae are formed by two rows of areolae arranged alternately. The striae are radiate to strongly radiate at the footpole. Longitudinal lines are present on either side of the axial area, and may be indistinct in some specimens. The apical pore field is distinct and bi-lobed. The apiculate headpole may be strongly or weakly developed, and the expanded portion of the valve (“shoulders”) near the headpole may be variable in is expression.

We exclude here the fossil specimens from Idaho cited by Kociolek and Stoermer (1988) as part of their concept of this taxon. Those are interpreted as a separate species.

Distribution: Verified only in Northwest Iowa.


Original Description

  • Basionym
    Gomphoneis eriense var. apiculata
  • Author
    Stoermer in Reimer 1982

Cite This Page

Kociolek, P. (2011). Gomphoneis eriense var. apiculata. In Diatoms of North America. Retrieved June 23, 2024, from https://diatoms.org/species/gomphoneis_apiculata


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