Epithemia adnata has finer striae (12-14 in 10 μm) than E. turgida (8-10 in 10 μm). In addition, E. adnata has 3-7 striae between adjacent costae, while E. turgida has 2-3 striae between adjacent costae. The valves of E. reichelti are more triangular in shape and the raphe canal is positioned on the dorsal margin.