1. North American subspecies of tundra swan having a soft whistling note
   - whistling swan

Type of: Cygnus columbianus, tundra swan

• genus Calophyllum
• genus Calopogon
• genus Calosoma
• genus Caltha
• genus Calvatia
• genus Calycanthus
• genus Calycophyllum
• genus Calymmatobacterium
• genus Calypso
• genus Calystegia
• genus Camassia
• genus Cambarus
• genus Camelina
• genus Camellia
• genus Camelus
• genus Campanula
• genus Campephilus
• genus Camponotus
• genus Camptosorus
• genus Campyloneurum
• genus Campylorhynchus
• genus Canachites
• genus Cananga
• genus Canangium
• genus Canavalia