Valves trullate, with broadest portion of the valve outline located towards the footpole from the central nodule. Apices rounded. Raphe distinctly undulate, with rounded external proximal ends. The axial area is narrow, straight, expanded slightly to form a linear-ellipsoidal central area that bears a single, relatively large stigma. A longitudinal line is positioned next to, or near, the axial area. Striae are distinctly biseriate, radiate near the central area, becoming parallel then radiate at the headpole, and becoming strongly radiate at the footpole. A distinct apical pore field is present at the footpole.
From2/10/2011 until 11/22/2024, this taxon appeared as Gomphoneis eriense var. angularis. The specific epithet is now corrected to "eriensis". - S. Spaulding
Kociolek, P. (2011). Gomphoneis eriensis var. angularis. In Diatoms of North America. Retrieved November 23, 2024, from https://diatoms.org/species/gomphoneis_eriensis_angularis
The 15 response plots show an environmental variable (x axis) against the relative abundance (y axis) of Gomphoneis eriensis var. angularis 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.