Compare Achnanthidium crassum
Compare
Achnanthidium crassum is difficult to distinguish, except under optimal illumination. Achnanthidium rivulare has a slightly smaller length-to-width ratio and parallel striae at the apices on the raphe valve. Achnanthidium deflexum has subrostrate ends, areolae that are resolvable in LM and shortened marginal striae in the center of the valve. Achnanthidium pyrenaicum has slightly rostrate ends and a fascia on the raphe valve.
LM scalebar = 10 µm
Length Range
7.3-19.6 µm
7.3-19.6 µm
Width Range
3.1-4.5 µm
3.1-4.5 µm
Striae in 10 µm
17-24
17-24
Achnanthidium rivulare
Length Range
5.4-23.8 µm
5.4-23.8 µm
Width Range
2.6-4.4 µm
2.6-4.4 µm
Striae in 10 µm
19-25 in the middle of raphe valve, 19-28 in the middle of the rapheless valve
19-25 in the middle of raphe valve, 19-28 in the middle of the rapheless valve
Achnanthidium deflexum
Length Range
7.4-28.3 µm
7.4-28.3 µm
Width Range
3.1-5.3 µm
3.1-5.3 µm
Striae in 10 µm
15-28 in the middle of raphe valve
15-28 in the middle of raphe valve
Achnanthidium pyrenaicum
Length Range
10–16 µm
10–16 µm
Width Range
2.5-4.0 µm
2.5-4.0 µm
Striae in 10 µm
20-25 in the center, 34-40 at the raphe valve ends; 20-28 in the center, 32-38 at the rapheless valve ends
20-25 in the center, 34-40 at the raphe valve ends; 20-28 in the center, 32-38 at the rapheless valve ends