| Reported in | Status | Registered by | ||
|---|---|---|---|---|
| Clostridium coccoides | Unknown | Valid (ICNP) | Excubia bot about 3 years ago | |
| Clostridium clostridioforme | Unknown | Valid (ICNP) | Excubia bot about 3 years ago | |
| Clostridium clostridiiforme | Unknown | Valid (ICNP) | Excubia bot about 3 years ago | |
| Clostridium clariflavum | Unknown | Valid (ICNP) | Excubia bot about 3 years ago | |
| Clostridium citroniae | Unknown | Valid (ICNP) | Excubia bot about 3 years ago | |
| Clostridium cellulolyticum | Unknown | Valid (ICNP) | Excubia bot about 3 years ago | |
| Clostridium cellobioparum | Unknown | Valid (ICNP) | Excubia bot about 3 years ago | |
| Clostridium celerecrescens | Unknown | Valid (ICNP) | Excubia bot about 3 years ago | |
| Clostridium caminithermale | Unknown | Valid (ICNP) | Excubia bot about 3 years ago | |
| Clostridium caldaquaticum | Unknown | Valid (ICNP) | Excubia bot about 3 years ago | |
| Clostridium caenicola | Unknown | Valid (ICNP) | Excubia bot about 3 years ago | |
| Clostridium bryantii | Unknown | Valid (ICNP) | Excubia bot about 3 years ago | |
| Clostridium bolteae | Unknown | Valid (ICNP) | Excubia bot about 3 years ago | |
| Clostridium bifermentans | Unknown | Valid (ICNP) | Excubia bot about 3 years ago | |
| Clostridium bartlettii | Unknown | Valid (ICNP) | Excubia bot about 3 years ago | |
| Clostridium barkeri | Unknown | Valid (ICNP) | Excubia bot about 3 years ago | |
| Clostridium barati | Unknown | Valid (ICNP) | Excubia bot about 3 years ago | |
| Clostridium asparagiforme | Unknown | Valid (ICNP) | Excubia bot about 3 years ago | |
| Clostridium articum | Unknown | Valid (ICNP) | Excubia bot about 3 years ago | |
| Clostridium arcticum | Unknown | Valid (ICNP) | Excubia bot about 3 years ago | |
| Clostridium amygdalinum | Unknown | Valid (ICNP) | Excubia bot about 3 years ago | |
| Clostridium ammoniilyticum | Unknown | Valid (ICNP) | Excubia bot about 3 years ago | |
| Clostridium aminovalericum | Unknown | Valid (ICNP) | Excubia bot about 3 years ago | |
| Clostridium alkalicellum | Unknown | Valid (ICNP) | Excubia bot about 3 years ago | |
| Clostridium alkalicellulosi | Unknown | Valid (ICNP) | Excubia bot about 3 years ago | |
| Clostridium algidixylanolyticum | Unknown | Valid (ICNP) | Excubia bot about 3 years ago | |
| Clostridium aldrichii | Unknown | Valid (ICNP) | Excubia bot about 3 years ago | |
| Clostridium aldenense | Unknown | Valid (ICNP) | Excubia bot about 3 years ago | |
| Clostridium aerotolerans | Unknown | Valid (ICNP) | Excubia bot about 3 years ago | |
| Clostridium acidurici | Unknown | Valid (ICNP) | Excubia bot about 3 years ago |