This variety has been reported as Fragilaria construens var. minuta Temp.& Perag. (Stoermer and Yang1969). Based on preliminary observations and genus description of Williams and Round (1987), it may be more appropriate in the genus Staurosira . However, further investigation is necessary before the transfer can be made.
This variety is smaller than the nominate. Its valves are elliptical to lanceolate is shape and has finer striae than the nominate (16-20 striae in 10 micrometers)(Stoermer and Yang1969). This variety is most closely related to Staurosira construens var. venter but does have a narrower valve and finer striae.