Gomphoneis eriense var. variabilis
Kociolek and Stoermer 1988 Category: Asymmetrical biraphid
BASIONYM: Gomphoneis eriense var. variabilis Kociolek and Stoermer 1988
LM scalebar = 10 µm = 80 pixels.
Observations
Contributor: Pat Kociolek - February 2011
Length Range: 25-45 µm
Width Range: 9.5-12 µm
Striae in 10 µm: 10-13 in the center, 14-16 at the poles
Description
Valves are lanceolate-clavate, with a distinctly protracted, broadly rounded head-pole, a robust to linear central portion of the valve and a distinctly rounded footpole. Smaller valves are elliptical-clavate, with the headpole protracted slightly. Striae are radiate at the central portion of the valve and strongly radiate at the poles. The raphe is undulate and lateral. The axial area is narrow, widening slightly towards the central area. A small, barely circular central area with a single stigma is present. The striae have individual areolae observable with DIC or oblique light in the light microscope. Longitudinal lines are distinct near the axial area, less so at the apices. Apical pore fields are present at the footpole.
Gomphoneis eriense var. variabilis is widely distributed throughout western North America.
Original Description
Basionym: Gomphoneis eriense var. variabilis
Author: Kociolek and Stoermer 1988
Length Range: µm
Striae in 10 µm:
Original Description
Original Images
Cite This Page:
Kociolek, P. (2011). Gomphoneis eriense. In Diatoms of the United States. Retrieved December 10, 2013, from http://westerndiatoms.colorado.edu/taxa/species/gomphoneis_variabilis
Species: Gomphoneis eriense
Contributor: Pat Kociolek
Reviewer: Sam Rushforth
Image Credit: Pat Kociolek
- Valves lanceolate-clavate
- Longitudinal lines distinct near the axial area
- Striae 10-13 in the center valve, 14-16 at the poles
Valves are lanceolate-clavate. Smaller valves are elliptical-clavate, with the headpole protracted slightly. Striae are radiate at the central portion of the valve and strongly radiate at the poles. A small, barely circular central area with a single stigma is present. Longitudinal lines are distinct near the axial area, less so at the apices.
Compare
Gomphoneis eriense var. variabilis is distinguished from other taxa considered within the basionym for this taxon. It differs from G. eriense var. angularis and G. eriense var. rostrata in that the valves are more rounded and have the broadest portion of the valve at the center. Gomphoneis eriense var. variabilis is distinguished from G. subherculeana by being narrower, and having finer striae. Gomphoneis eriense var. variabilis is distinguished from G. septa by smaller valves that are more broadly rounded.
This species has been confused with taxa in Gomphonema, specifically G. ventricosum and G. manubrium. Unlike those species, Gomphoneis eriense var. variabilis has longitudinal lines and striae composed of doubly-punctate striae.
Gomphoneis eriense var. angularis
Gomphoneis septa
Gomphoneis subherculeana
Kociolek & Stoermer
Gomphonema manubrium
Fricke
Citations
Kociolek, J.P. and Stoermer, E.F. (1988). Taxonomy, ultrastructure and distribution of Gomphoneis herculeana, G. eriense and closely related species (Naviculales: Gomphonemataceae). Proc. Acad. Nat. Sci. Phil. 140: 24-97. http://www.jstor.org/stable/4064935
Links & ID's
Index Nominum Algarum (INA)
California Academy of Sciences (CAS)
Gomphoneis eriense var. variabilis CAS
North American Diatom Ecological Database (NADED)
NADED ID: 36002