Northern Prairie Wildlife Research Center
| Lead | Characteristic | Go To |
| 1 | Lip yellow. | C. calceolus |
| 1 | Lip predominantly white, with pink or purple markings. | Lead 2 |
| 2 | Sepals and lateral petals white; lip 3-5 cm long. | C. reginae |
| 2 | Sepals and lateral petals greenish; lip 1.5-2 cm long. | C. candidum |