Rexlowea navicularis
Kociolek and Thomas 2010 Category: Symmetrical biraphid
BASIONYM: Navicula semen Ehrenberg 1841
SYNONYM(S): Placoneis navicularis (Ehrenberg) Cox 2003
LM scalebar = 10 µm = 40 pixels.
Observations
Contributor: Pat Kociolek - March 2011
Length Range: 44–132 µm
Width Range: 18–30 µm
Striae in 10 µm: 5–6 in the center, 20 at the apices
Description
Valves are broadly lanceolate, with apices protracted to broadly rounded. The axial area is narrow and straight, forming a narrow, linear to ovoid central area. The raphe is lateral and undulate, with large, rounded external proximal ends and hooked external distal ends. Striae are radiate, with the 1st or 2nd stria at each apex parallel or, rarely, convergent. Within a stria, the marginal areola are large and coarsely arranged. The middle portion has areola comparatively smaller and rounded, and the areolae near the axial area form two rows per stria. The central area has large, round, isolated puncta. The smallest striae at the apices are multiseriate throughout their length.
Original Description
Basionym: Navicula semen
Author: Ehrenberg 1841
Length Range: µm
Striae in 10 µm:
Original Description
Original Images
Cite This Page:
Kociolek, P. (2011). Rexlowea navicularis . In Diatoms of the United States. Retrieved June 19, 2013, from http://westerndiatoms.colorado.edu/taxa/species/rexlowea_navicularis1
Species: Rexlowea navicularis
Contributor: Pat Kociolek
Reviewer: Sam Rushforth
Image Credit: Pat Kociolek
- Apices protracted to broadly rounded
- Proximal raphe ends large, rounded
- Central area with isolated puncta
- Raphe lateral
- Raphe undulate
Valves are broadly lanceolate with apices protracted to broadly rounded. The raphe is lateral and undulate. Within a stria, the marginal areolae are large and more coarsely arranged. The middle valve has areolae comparatively smaller and rounded. Central area has large, round isolated puncta. The smallest striae at the apices are multiseriate throughout their length.
Compare
The large size and distinct structure of this species makes it easy to distinguish from other naviculoid diatoms.
Citations
Kociolek, J.P. and Thomas, E.W. (2010). Taxonomy and ultrastructure of five naviculoid diatoms (class Bacillariophyceae) from the Rocky Mountains of Colorado (USA), with the description of a new genus and four new species. Nova Hedwigia 90:195-214. 10.1127/0029-5035/2010/0090-0195
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.
Patrick, R.M. and Reimer, C.W. (1966). The Diatoms of the United States exclusive of Alaska and Hawaii, V. 1. Monographs of the Academy of Natural Sciences of Philadelphia 13.
Links & ID's
Index Nominum Algarum (INA)
California Academy of Sciences (CAS)
North American Diatom Ecological Database (NADED)
NADED ID: 93028