Krammer 1997 Category: Asymmetrical biraphid
BASIONYM: Encyonopsis cesatiformis Krammer 1997
REPORTED AS: Encyonopsis montana (Bahls 2013, figs. 89, 90) | Encyonopsis cesatii var. geitleri (Bahls 2012, Diatoms of the US) | Encyonopsis montana (Bahls 2013, Diatoms of the US)
Contributor: Loren Bahls - June 2014
Length Range: 26-43 µm
Width Range: 5.4-7.6 µm
Striae in 10 µm: 17-19 near the valve center, 19-21 near the ends
Valves are broadly lanceolate and nearly symmetric with respect to the apical axis. Apices are rostrate and deflected slightly to the ventral side. The axial area is narrow. The central area is small and asymmetric, rounded on the dorsal side and the ventral side with two or three shortened striae. The raphe is weakly lateral. Proximal raphe ends are deflected toward the dorsal side and distal raphe ends are hooked toward the ventral side. Striae are radiate throughout. Areolae are very fine and difficult to resolve in LM.
Basionym: Encyonopsis cesatiformis
Author: Krammer 1997
Length Range: 26-49 µm
Width Range: 6.9-9.0 µm
Striae in 10 µm: 16-17
Bahls, L. (2013). Encyonopsis from western North America: 31 species from Alberta, Idaho, Montana, Oregon, South Dakota, and Washington, including 17 species described as new. Northwest Diatoms, Volume 5. The Montana Diatom Collection, Helena, 46 pp.
Krammer, K. (1997). Die cymbelloiden Diatomeen. Eine Monographie der weltweit bekannten Taxa. Teil 2. Encyonema part., Encyonopsis and Cymbellopsis. Bibliotheca Diatomologica 37:1-469.
Encyonopsis cesatiformis was collected from a wetland and a small pond (pictured below) in Glacier National Park, Montana. The pH of the pond on the collection date was 7.78 and the specific conductance measured 139 µS/cm. Encyonopsis cesatiformis was described from material collected from a wetland in Finnish Lapland. It is also found in the European Alps. Krammer (1997) describes its preferred habitat as oligotrophic waters with low electrolyte content.
Kootenai Pond, Glacier National Park, Montana: home of Encyonopsis cesatiformis.
Credit/Source: Loren Bahls