Lange-Bertalot et Metzeltin 1996 Category: Symmetrical biraphid
TYPE SPECIES: Geissleria moseri Metzeltin Witkowski et Lange-Bertalot in Lange-Bertalot et Metzeltin
Geissleria valves are elliptical to linear-elliptical, becoming obtuse, broadly rounded or rostrate at the ends. The striae are comprised of fine lineolate areolae; aerolae 50-80 in 10 µm. Distinctive annulae are present at the poles. The annulae are comprised of one to four transapical striae that interrupt the typical striae. The raphe is straight and filiform, with straight proximal ends. Terminal raphe ends are deflected. An isolated punctum may be present or absent in the central area.
Geissleria includes species that were formerly included in the ‘Annulatae’ section of Navicula, including Navicula paludosa (Hustedt) andN. similis Krasske. Geissleria species are broadly distributed over a range of oliogotrophic to eutrophic waters, but are locally rare in abundance. Species level ecological preferences may be more specific.
Cite This Page:
Spaulding, S., and Edlund, M. (2009). Geissleria. In Diatoms of the United States. Retrieved July 05, 2015, from http://westerndiatoms.colorado.edu/taxa/genus/Geissleria