Hygropetra balfouriana
Krammer and Lange-Bertalot 2000 Category: Symmetrical biraphid
BASIONYM: Pinnularia balfouriana Grunow ex Cleve 1895
LM scalebar = 10 µm = 80 pixels.
Observations
Contributor: Pat Kociolek - January 2011
Length Range: 5-19 µm
Width Range: 3-5 µm
Striae in 10 µm: 10-12
Description
Valves are broadly linear to nearly elliptical in outline with rounded ends. The axial area narrow at the poles, widening to form a linear-elliptical to lanceolate central area. The raphe is straight, filiform, with distal ends not reaching the apices. The proximal raphe ends terminating quite a distance from one another. Striae are prominent, without visible punctuation in the LM, and radiate throughout.
Comments: Valve ultrastructure was used (Krammer 2000) to differentiate this genus from Pinnularia; this is the only species of the genus known in the US flora. This taxon is found in cool or mountainous regions across the US.
Original Description
Basionym: Pinnularia balfouriana
Author: Grunow ex Cleve 1895
Length Range: µm
Striae in 10 µm:
Original Description
Original Images
Cite This Page:
Kociolek, P. (2011). Hygropetra balfouriana. In Diatoms of the United States. Retrieved May 24, 2013, from http://westerndiatoms.colorado.edu/taxa/species/hygropetra_balfouriana
Species: Hygropetra balfouriana
Contributor: Pat Kociolek
Reviewer: Marina Potapova
Image Credit: Pat Kociolek
- Striae distinct
- Distal raphe ends subterminal
- Valves small
Valves broadly linear to nearly elliptical in outline. Raphe short, with the distal ends not reaching the apices. The proximal raphe ends terminate quite a distance from one another. Striae distinct and radiate.
Compare
Hygropetra balfouriana is the only species of the genus known in the US flora. This taxon can be distinguished in the LM from Pinnularia taxa by its small size and straight filiform raphe with subterminal distal raphe ends. Some specimens of this taxon have been confused with fragilarioid taxa due to the indistinct nature of the raphe in smaller specimens.
Citations
Krammer, K. (2000). The genus Pinnularia. The Diatoms of Europe. Diatoms of Inland Waters and Comparable Habitats 1: 1-703.
Krammer, K. and Lange-Bertalot, H. (1986). Bacillariophyceae. 1. Teil: Naviculaceae. In: Ettl, H., J. Gerloff, H. Heynig and D. Mollenhauer (eds.) Susswasserflora von Mitteleuropa, Band 2/1. Gustav Fisher Verlag, Jena. 876 pp.
Links & ID's
Index Nominum Algarum (INA)
California Academy of Sciences (CAS)
North American Diatom Ecological Database (NADED)
NADED ID: 221001