Contributor: Ian Bishop - January 2017
Length Range: 23-30 µm
Width Range: 4.0-4.5 µm
Striae in 10 µm: 12-15
Valves are clavate, with a rounded, rostrate to subcapitate headpole and narrowly rounded footpole. The axial area is wide and lanceolate. The raphe is lateral and mildly undulate. Striae are short and radiate at the footpole, short and weakly radiate between apices, and longer and parallel at the headpole. A single stigmoid is present.
Under SEM, exterior openings of areolae are C-shaped. Externally the stigmoid is small and circular, while internally the opening is slit-like. Helictoglossae are distinct at both valve ends and internal proximal raphe ends are unilaterally deflected and recurved.
Author: Stancheva and Kociolek 2016
Length Range: 17-31 µm
Width Range: 4-5.2 µm
Striae in 10 µm: 11-14
Liu, Y., Kociolek, J. P., & Wang, Q. (2013). Six new species of Gomphonema Ehrenberg (Bacillariophyceae) species from the Great Xing’an Mountains, Northeastern China. Cryptogamie, Algologie 34 (4): 301-324.
Stancheva, R., Sheath, R.G. and Kociolek, J.P. (2016). New freshwater gomphonemoid diatoms from streams in the Sierra Nevada mountains, California, USA. Phytotaxa 289 (2): 118-134.
Gomphonema sierrianum has been observed in the western and southeast United States. Populations in the west are rare, principally found in remote oligotrophic streams in the Sierra Nevada mountain range (Stancheva et al., 2016; personal observation). Populations in the southeast have been found throughout the Piedmont plateau, Blue Ridge, and Ridge and Valley upland areas (USGS SESQA survey).