Compare Aulacoseira granulata var. angustissima
Aulacoseira granulata var. angustissima has long, narrow valves with diameter of 2.5-4 μm and mantle height/valve diameter ratio greater than 3.2. Specimens with either valve diameter greater than 4 µm, or mantle height/valve diameter ratio lower than 3.2, or both, should be placed in A. granulata. Specimens of A. granulata var. angustissima with fine areolae can be confused with A. ambigua, which is recognizable by its hollow ringleiste and absence of long separation spines.
LM scalebar = 10 µm
Diameter
2.5-4 µm
2.5-4 µm
Width Range
8-20 µm
8-20 µm
Striae in 10 µm
10-20
10-20
Diameter
3-12 µm
3-12 µm
Width Range
5-15 µm
5-15 µm
Striae in 10 µm
17-22
17-22
Diameter
4-17 µm
4-17 µm
Width Range
4-20 µm
4-20 µm
Striae in 10 µm
8-18
8-18
