Identification

Description

Valves are linear-lanceolate, clavate, headpole and footpole are rounded. The axial area is lanceolate. The central area is linear-ellipitic and slightly asymmetric, with the side opposite the stigma larger than the side bearing the stigma. A single, large, distinct stigma is present at the central area. The raphe is lateral and weakly undulate to nearly straight. The external proximal raphe ends terminate close to one another. External distal raphe ends are deflected onto the mantle, to the side of the valve opposite the stigma. Striae are parallel to radiate at the center and towards the headpole, becoming more strongly radiate at the footpole. Striae number 13-15 in 10 µm. The apical pore field is bi-lobed and prominent.

Under SEM, the striae are doubly punctate.

Autecology

Original Description

  • Basionym
    Gomphonema occidentale var. abbreviate
  • Author
    M.Schmidt 1899

EMAP Assessment

EMAP Distribution

Gomphonema Stoermeri 40 Copy
Map 40

Response Plots

Gomphonema Stoermeri Copy

Cite This Page

Kociolek, P. (2011). Gomphonema stoermeri. In Diatoms of North America. Retrieved July 18, 2018, from https://diatoms.org/species/gomphonema_stoermeri

Responses

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