| Violaceae | |
Orthion caudatum
| Lundell | Wrightia 4(1): 38 | 1968 |
| Violaceae | |
Orthion cymosa
| | | |
| Violaceae | |
Orthion guatemalense
| Lundell | Phytologia 56(1): 29 | 1984 |
| Violaceae | |
Orthion malpighiifolium
| (Standl.) Standl. & Steyerm. | Publ. Field Mus. Nat. Hist., Bot. Ser. 22(4): 250 | 1940 |
| Violaceae | |
Orthion montanum
| Lundell | Wrightia 4(3): 115–116 | 1969 |
| Violaceae | |
Orthion oblanceolatum
| Lundell | Lloydia 4(1): 54 | 1941 |
| Violaceae | |
Orthion subsessile
| (Standl.) Steyerm. & Standl. | Publ. Field Mus. Nat. Hist., Bot. Ser. 22(4): 250 | 1940 |
| Violaceae | |
Orthion veracruzense
| Lundell | Phytologia 56: 31 | 1984 |