Contributor: Marina Potapova - January 2012
Length Range: 7-11 µm
Width Range: 4.4–5.0 µm
Striae in 10 µm: 26–30 on raphe valve, 12-15 on rapheless valve
Valves are elliptic. The raphe valve has a narrow linear axial area and a transversely rectangular central area. The raphe is filiform and straight with slightly expanded external distal and proximal ends. The internal proximal raphe ends are turned to opposite sides, while the internal distal ends have small helictoglossae. Striae are uniseriate and moderately radiate. The rapheless valve has a wide elliptic–lanceolate axial area and short triseriate striae.
Basionym: Platessa kingstonii
Author: Potapova 2012
Length Range: 7.4-11.0 µm
Width Range: 4.4-5.0 µm
Striae in 10 µm: 26-30 on raphe valve, 12-15 on rapheless valve
Potapova, M. (2012). New species and combinations in monoraphid diatoms (Family Achnanthidiaceae) from North America. Diatom Research 27(1): 29-42. doi:10.1080/0269249X.2011.644636
So far Platessa kingstonii has been found only in two streams in north–central Pennsylvania. Conductivity in these streams ranged from 19 to 38 μ S cm−1, and pH was 6.0–6.5.