Diatoms of North AmericaDiatoms of North America
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Guide to Krasskella

Ross and Sims 1978

Krasskella Guide
Credit: Ian Bishop, Sarah Spaulding
  1. Valves small
  2. Proximal raphe ends distant
  3. Striae composed of an elongate areola on valve face

Valves are small and elongate. The axial and central areas are linear. Striae composed of an elongate areola on valve face and a circular areola on the valve mantle. The proximal raphe ends distant and the raphe fissures are slightly oblique. Helictoglossae at the proximal and distal raphe ends are not well developed. Frustules rectangular in girdle view.

Krasskella currently includes only three species, K. kriegeriana, K. hyalina Carter and Denny and K. manguinii Lange-Bert. and Rumrich. The valves are small, and likely, have been overlooked in surveys. In North America, K. kriegeriana is not uncommon in cold, nutrient poor rivers of the California Sierra Nevada Range.