Krammer 2002 Category: Asymmetrical biraphid
BASIONYM: Cymbella maggiana Krammer 2002
Contributor: Loren Bahls - May 2016
Length Range: 29-78 µm
Width Range: 10.5-14.3 µm
Striae in 10 µm: 8-12 at the valve center, up to 14 near the apices
Valves are lanceolate and dorsiventral, with bluntly rounded apices. The dorsal margin is moderately arched. The ventral margin is nearly flat, with a slightly gibbous center. The axial area is narrow, barely wider than the raphe, and located just ventral to the valve mid line. The central area is small and rhombic in shape. The raphe is distinctly lateral, becoming reverse lateral at the proximal ends. Proximal raphe ends are deflected ventrally and terminate in small pores. Distal raphe fissures are filiform and deflected dorsally at about 45 degrees. Striae are radiate throughout, and more strongly radiate near the apices. Areolae are distinct in LM and number 18-24 in 10 µm. Isolated stigmata number 2-5 at the proximal ends of the median ventral striae.
Basionym: Cymbella maggiana
Author: Krammer 2002
Length Range: 43-63 µm
Width Range: 10.5-12.7 µm
Striae in 10 µm: 10-12 at the valve center, up to 15 near the apices
Krammer, K. (2002). The genus Cymbella. Diatoms of Europe. Diatoms of the European Inland Waters and Comparable Habitats 3: 1-584.
Cymbella maggiana has been collected from two streams in adjacent watersheds of Glacier National Park, Montana. These streams–Logging Creek and Quartz Creek–are on the west side of the Park in the Flathead River drainage. At the time of collection, pH and specific conductance measured 7.74 and 50 µS/cm, respectively, in one of these streams (Logging Creek). The type locality of this species is the River Maggia in Ticino, Switzerland. Krammer (2002) reports that this species is found in several oligotrophic alpine rivers in this region of the Alps.