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Gomphonema elongatum is present in the eastern US. It is distinguished from both G. acuminatum and G. coronatum by its more linear outline.

LM scalebar = 10 µm
Acuminatumelongatum Wsmith 317003 Acuminatumelongatum Wsmith 317002 Acuminatumelongatum Wsmith 317004 Acuminatumelongatum Wsmith 317007 Acuminatumelongatum Wsmith 317005 Acuminatumelongatum Wsmith 317006
Length Range
40-105 µm
Width Range
7-11 µm
Striae in 10 µm
13-15

Gomphonema acuminatum

Ehrenb. 1832

Gomphonema Acuminatum 002 Gomphonema Acuminatum 001 Gomphonema Acuminatum 003 Gomphonema Acuminatum 005 Acuminatum Gc109928B004 Gomphonema Acuminatum 004
Length Range
19-77 µm
Width Range
7-12 µm
Striae in 10 µm
9-12 at the center, 12-14 towards the footpole

Gomphonema coronatum

Ehrenb. 1840

Coronatum Gc4367A006 Coronatum Gc4367A007 Coronatum Gc4367A003 Coronatum Gc1283004 Coronatum Gc1283002 Coronatum Gc1283001
Length Range
34-108 µm
Width Range
8-13 µm
Striae in 10 µm
8-12, approaching 15/10 ┬Ám at the footpole