• Category
  • Length Range
    9.4-13.1 µm
  • Width Range
    2.9-3.5 µm
  • Striae in 10 µm
  • Reported As
    Nitzschia sinuata var. delognei (Lange-Bertalot 1980, p. 54-55; Figs 77-86, 155, 156)



Valves are small and lanceolate. Larger valves have protracted apices, which can be recurved dorsally. Striae are weakly radiate. Areolae are coarse and irregularly spaced, particularly near the apical axis. Fibulae are coarse and extend approximately to the apical axis, numbering 6-7 in 10 µm.

This taxon is often reported as Nitzschia sinuata var. delognei (e.g. Krammer and Lange-Bertalot 1988; Potapova and Charles 2003, Morales and Vis 2007), and is considered to be closely related to other taxa in the Nitzschia sinuata group, including N. sinuata var. sinuata and N. sinuata var. tabellaria. However, upon closer ultrastructural examination under SEM, Kobayasi and Kobori (1990) determined that N. sinuata var. delognei differs considerably from the nominate variety, most prominently in terms of areolar occlusion (N. sinuata var. delognei has them, N. sinuata does not). This difference was used to argue that N. sinuata var. delognei should not be considered a variety within the N. sinuata, but rather separated and raised to the rank of species. Cleve-Euler was the first to recognize this taxon at the specific rank and used the specific epithet "solgensis" because an "N. delognei" already existed at the time of publication.


This taxon has a broad North American distribution (reported as Nitzschia sinuata var. delognei) from the Pacific Northwest (personal observation), the Laurentian Great lakes (Stoermer et al. 1999), to the southeastern Piedmont and southern Appalachian regions (Bishop et al., accepted). Potapova and Charles (2003) report a conductivity optimum for this taxon of 335 μS cm-1. It has also been reported as indicative of low total phosphorus levels in samples collected across the United States and in the central and western plains in particular (Potapova and Charles 2007).

Original Description

  • Basionym
    Nitzschia solgensis
  • Author
    A.Cleve 1952

Cite This Page

Bishop, I. (2017). Grunowia solgensis. In Diatoms of North America. Retrieved July 21, 2018, from https://diatoms.org/species/grunowia_solgensis


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