Compare

Gomphonema caperatum has shorter, more narrow valves, and a more broadly lanceolate axial area. Gomphonema christenseni lacks a stigmoid and the headpole end is more tapered. Gomphonema incognitum is smaller in both length and width. Gomphonema insularum has shorter, more narrow valves, a more broadly lanceolate axial area that does not expand into a defined central area and a sinuous raphe. Gomphonema stoermeri has shorter, more narrow valves, a narrower axial area, and a smaller central area. Gomphonema amerhombicum has more finely spaced striae (>14 in 10 µm) and the footpole has somewhat concave margins.

LM scalebar = 10 µm
Gc53921  Gomphonema Freesei 1 Gc53921  Gomphonema Freesei 2 Gc53921  Gomphonema Freesei 3 Gc53921  Gomphonema Freesei 4 Holotype Gc53921  Gomphonema Freesei 4B Holotype Gc53921  Gomphonema Freesei 5
Length Range
35.0-53.9 µm
Width Range
6.5-7.5 µm
Striae in 10 µm
12.1-14.5 at valve center, 14.2-16.2 at headpole, 11.7-15.4 at footpole

Gomphonema caperatum

Ponader and Potapova 2017

G Caperatum 15576A 08142015 08 Cl G Caperatum 15971A 04082016 01 G Caperatum 15577A 08172015 06 Cl G Caperatum 15558A 08132015 56 Cl G Caperatum 14368 12122016 02 Cl G Caperatum 15959A 04042016 33 Cl G Caperatum 15963A 04052016 02 Cl
Length Range
22.4-31.9 µm
Width Range
4.4-5.2 µm
Striae in 10 µm
14-16

Gomphonema christenseni

R.L.Lowe and Kociolek 1984

Gomphonema christenseni LM2 Gomphonema christenseni LM5 Gomphonema christenseni LM6 4 53920  Gchristenseni Holo 5 53920  Gchristenseni2 6 53920  Gchristenseni2 7 53920  Gchristenseni2
Length Range
32.8-57.4 µm
Width Range
6.1-7.8 µm
Striae in 10 µm
13-16

Gomphonema incognitum

E.Reichardt, Jüttner and E.J.Cox 2004

G Incog 15620A 10132015 12 Cl G Incog 15576A 08142015 20 Cl G Incog 15576A 08142015 37 Cl G Incog 15576A 08142015 21 Cl G Incog 15558A 08132015 42 Cl G Incog 15576A 08142015 29 Cl G Incognito Lm6
Length Range
17.8-29.5 µm
Width Range
5.0-5.8 µm
Striae in 10 µm
13-16 at mid-valve; up to 18 at the apices

Gomphonema insularum

Kociolek, Woodward and Graeff 2016

Gomphonema insularum LM1 Gomphonema insularum LM2 Gomphonema insularum LM3 Gomphonema insularum LM4 Gomphonema insularum LM5 Gomphonema insularum LM6 Gomphonema insularum LM7
Length Range
15.2-42 µm
Width Range
4.4-7 µm
Striae in 10 µm
13-16

Gomphonema stoermeri

Kociolek and Kingston 1999

Gomphonema stoermeri LM7 Gomphonema stoermeri LM2 Gomphonema stoermeri LM3 Gomphonema stoermeri LM5 Gomphonema stoermeri LM1
Length Range
19-45 µm
Width Range
4-6 µm
Striae in 10 µm
13-15

Gomphonema amerhombicum

E.Reichardt 2007

G Amerhombicum  B Isotype 20170301 06 Cl G Amerhombicum  A Isotype 20170301 08 Cl G Amerhombicum  A Isotype 20170301 18 Cl G Amerhombicum  B Isotype 20170301 05 Cl G Amerhombicum  B Isotype 20170301 14 Cl G Amerhombicum  B Isotype 20170301 09 Cl G Amerhombicum  B Isotype 20170301 21 Cl
Length Range
22.5-60 µm
Width Range
5.6-7.7 µm
Striae in 10 µm
13-15 at mid-valve, up to 17 at headpole