Compare

Sellaphora bacillum is similar in shape, but has a distinct canopeum around the central area, lower stria density and more acutely rounded apices. Sellaphora alastos and S. americana are similar in shape, however they have a distinct canopeum and broader valves. Sellaphora pupula is similar in striae ornamentation, but has protracted apices, an elliptic-lanceolate valve shape and polar bars that wrap around the apices. Sellaphora fusticulus is similar in shape and stria ornamentation, but has a rhombic central area with 4-6 striae bordering the central area.

LM scalebar = 10 µm
Sellaphora laevissima LM20 Sellaphora laevissima LM3 Sellaphora laevissima LM6 Sellaphora laevissima LM10 Sellaphora laevissima LM16
Length Range
32-53 µm
Width Range
8.0-10.6 µm
Striae in 10 µm
17-19

Sellaphora bacillum

(Ehrenb.) D.G.Mann 1989

Sellaphora bacillum LM4 Sellaphora bacillum LM6 Sellaphora bacillum LM3 Sellaphora bacillum LM5 Sellaphora bacillum LM2 Sellaphora bacillum LM1
Length Range
30-45 µm
Width Range
9-10 µm
Striae in 10 µm
12-14

Sellaphora alastos

(M.H.Hohn and Hellerman) Lange-Bert. and Metzeltin 1996

Sellaphora alastos LM1 Sellaphora alastos LM2 Sellaphora alastos LM3 Sellaphora alastos LM4 Sellaphora alastos LM5 Sellaphora alastos LM6 Sellaphora alastos LM7
Length Range
41.0-82.0 µm
Width Range
11.0-17.0 µm
Striae in 10 µm
17-19 midway between valve center and apex

Sellaphora americana

(Ehrenb.) D.G.Mann 1989

Sellaphora americana LM5 Sellaphora americana LM4 Sellaphora americana LM8 Sellaphora americana LM7 Sellaphora americana LM6 Sellaphora americana LM3 Sellaphora americana LM9
Length Range
58.3-93.4 µm
Width Range
14.6-19.1 µm
Striae in 10 µm
16-18 midway between valve center and apex

Also compare to

Sellaphora pupula

(Kütz.) Mereschk.

Sellaphora fusticulus

(Østrup) Lange-Bert.