Geissleria ignota
(Krasske) Lange-Bertalot and Metzeltin 1996 Category: Symmetrical biraphid
BASIONYM: Navicula ignota Krasske 1932
LM scalebar = 10 µm = 80 pixels.
Observations
Contributor: Rex Lowe - December 2011
Length Range: 16-18 µm
Width Range: 3.0-3.2 µm
Striae in 10 µm: 15-16
Description
Valves are triundulate with rostrate to subcapitate ends. The central area is expanded laterally with 2-4 shortened striae at the valve margin. The striae are radiate near the center of the valve becoming parallel near the ends. Two to three rows of annulae are at each apex of the valve.
Original Description
Basionym: Navicula ignota
Author: Krasske 1932
Length Range: 17-25 µm
Width Range: 4.5-5 µm
Striae in 10 µm: 12-14
Original Description
Linear, dreiwellig, Enden gerundet. Lang 17-25µ, breit 4,5-5µ. 12-14 Streifen in 10 µ, gebogen, die konvexe Seite den Enden zugewandt, die mittelsten stark verkürzt, so daB sich die schmale, lineare Längsarea in der Mitte fast bis zum Rande erweitert. Die mittleren Streifen konvergierend , gegen die Enden senkrecht zur Raphe.
Original Images
Cite This Page:
Lowe, R. (2011). Geissleria ignota. In Diatoms of the United States. Retrieved June 18, 2013, from http://westerndiatoms.colorado.edu/taxa/species/geisleria_ignota
Species: Geissleria ignota
Contributor: Rex Lowe
Reviewer: Sarah Spaulding
Image Credit: Rex Lowe
- Valves triundulate
- Central area expanded
- Striae radiate near center, becoming parallel near apices
- 2-3 rows of annulae
Valves triundulate with rostrate to subcapitate ends. The central area is expanded laterally with 2-4 shortened striae at the valve margin. Striae are radiate near the center of the valve, becoming parallel near the ends. Two to three rows of annulae are present at each apex of the valve.
Compare
Geissleria ignota is similar in size to G. paludosa, but G. ignota has triundulate valves.
Geissleria paludosa
(Hustedt) Lange-Bertalot et Metzeltin
Citations
Krasske, G. (1932). Beiträge zur Kenntnis der Diatomeenflora der Alpen. Nova Hedwigia 72(3): 92-135.
Lange-Bertalot, H. and Metzeltin, D. (1996). Indicators of oligotrophy - 800 taxa representative of three ecologically distinct lake types, Carbonate buffered - Oligodystrophic - Weakly buffered soft water. Lange-Bertalot, H. (ed.), Iconographia Diatomologica. Annotated Diatom Micrographs. Vol. 2. Ecology, Diversity, Taxonomy. Koeltz Scientific Books. Königstein, Germany, 2:390 pp.
Links & ID's
Index Nominum Algarum (INA)
California Academy of Sciences (CAS)
North American Diatom Ecological Database (NADED)
NADED ID: 210005