Dictionaries, Thesauruses, Pictures, and Press Releases
- Cleland, Ralph Erskine
- Clément, Nicholas
- Cleptidae
- Clerck, Carl Alexander
- Cleridae
- Clerodendron
- Clesch, Rudolf Friedrich Alfred
- Clethraceae
- Cleveland, Parker
- Clifdenian
- Clift, William
- Cliftonia monophylla
- Climacium
- Climacteridae
- Climacteris
- CLIMAP
- CLIMAPP
- CLIMAPP
- Climate/Long-range Investigation Mapping and Predictions Project
- Climate/Long-ranged Investigation Mapping and Predictions Project