Diatoms of North AmericaDiatoms of North America
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Compare Placoneis amphibola

(Cleve) E.J.Cox 2003

Compare

Placoneis gastrum is smaller, with broader apices and finer areola density (24-27 in 10 µm). Placoneis abiskoensis has parallel sides and capitate apices. Rexlowea navicularis has more linear-lanceolate valves, an oval central area and finer stria and areola density.

LM scalebar = 10 µm
Placoneis amphibola LM4 Placoneis amphibola LM3 Placoneis amphibola LM2 Placoneis amphibola LM5 Placoneis amphibola LM1 928 46 4 Plac Amphibola 779 39 0 Plac Amphibola
Length Range
39-66 µm
Width Range
21.6-25.6 µm
Striae in 10 µm
5.5-8.5

Placoneis abiskoensis

(Hust.) Lange-Bert. and Metzeltin 1996

Placoneis abiskoensis LM4 Placoneis abiskoensis LM3 Placoneis abiskoensis LM2 Placoneis abiskoensis LM1
Length Range
33.3-46.0 µm
Width Range
8.4-11.1 µm
Striae in 10 µm
10-12

Placoneis gastrum

(Ehrenb.) Mereschk. 1903

Placoneis gastrum LM6 Placoneis gastrum LM5 Placoneis gastrum LM4 Placoneis gastrum LM3 Placoneis gastrum LM2 Placoneis gastrum LM1
Length Range
30.2-55.8 µm
Width Range
15.9-20.0 µm
Striae in 10 µm
7-9 near the center, up to 10 near the apices

Rexlowea navicularis

Kociolek and Thomas 2010

Rexlowea navicularis LM2 Rexlowea navicularis LM3 Rexlowea navicularis LM5 Rexlowea navicularis LM1 Rexlowea navicularis LM4
Length Range
44–132 µm
Width Range
18–30 µm
Striae in 10 µm
5–6 in the center, 20 at the apices