Compare Cocconeis czarneckii
Compare
This taxon is a member of the Cocconeis placentula species complex (also termed sensu lato). Note that for practical purposes, diatoms.org presents several varieties and species within the species complex. We recommend such treatment for assessment programs.
For those who wish to distinguish species in the strict sense (termed sensu stricto), the details are here.
The rapheless valves of C. placentula and C. placentula var. euglypta have a maximum of six longitudinal lines per hemivalve.
The valves of Cocconeis lineata and C. coreana are more elongate, elliptic, proportionally longer, and have more rounded apices.
The largest valves of C. czarneckii have a similar pattern in areolae to C. klamathensis and C. grovei. Cocconeis klamathensis, however, has large, strongly arched valves and C. grovei has larger valves, with lower stria density.
LM scalebar = 10 µm
Length Range
17.7-51 µm
17.7-51 µm
Width Range
11.3-37.9 µm
11.3-37.9 µm
Striae in 10 µm
Raphe valve 18-30, rapheless valve 20-26
Raphe valve 18-30, rapheless valve 20-26
Cocconeis placentula sensu lato
Length Range
9-68 µm
9-68 µm
Width Range
7-32 µm
7-32 µm
Striae in 10 µm
20-24 on raphe valve, 15-25 on rapheless valve
20-24 on raphe valve, 15-25 on rapheless valve
Cocconeis grovei
Length Range
45-78 µm
45-78 µm
Width Range
30-56 µm
30-56 µm
Striae in 10 µm
14-17 raphe valves, 14-22 rapheless valves
14-17 raphe valves, 14-22 rapheless valves
Cocconeis coreana
Length Range
21-58 µm
21-58 µm
Width Range
11.5-36.6 µm
11.5-36.6 µm
Striae in 10 µm
18-24 raphe valve, 18-24 rapheless valve
18-24 raphe valve, 18-24 rapheless valve
Cocconeis cascadensis
Length Range
15.7-40 µm
15.7-40 µm
Width Range
8.7-22 µm
8.7-22 µm
Striae in 10 µm
Raphe valve 15-18.5, rapheless valve 7–12
Raphe valve 15-18.5, rapheless valve 7–12
Also compare to
Cocconeis placentula var. euglypta
BioData Reference
Krammer and Lange-Bertalot 2/4 Pl 53 Fig 1-19