|   C. abbreviatum
 v. abbreviatum ?
 19 x 18 μm
 single pyrenoid
 Kaga
 Ishikawa, 2000
 |   C. abbreviatum
 v. abbreviatum ?
 12-14 x 12-13 μm
 near Suga-daira m.
 Ueda
 Nagano, 2006
 
  |   C. abbreviatum
 var.  ?
 13 x 10 μm
 Shimo-no-koike
 Shiga highland
 Nagano, 2004
 |   C. abbreviatum
 v. germanicum
 12.5 x 11 μm
 Hasu-ike
 Shiga highland
 Nagano, 2005
 | 
|   C. abbreviatum
 v. germanicum
 16 x 14 μm
 rice field
 Ichinoseki
 Iwate, 2005
 |   C. abbreviatum
 v. germanicum
 μm
 Saiko 2
 Toda
 Saitama, 2007
 
  |   C. abbreviatum
 f. pygmaea
 μm
 Ohyachi 2
 Hachimantai
 Akita, 2007
 
  |   C. abbreviatum
 f. pygmaea
 μm
 Ochiai-numa 2
 Noshiro
 Akita, 2007
 
  | 
|   C. abbreviatum ?
 14 x 11 μm
 rice field
 Ichinoseki
 Iwate, 2005
 |