| Houstonia caerulea L. | |
| Houstonia longifolia Gaertn. | |
| Houstonia purpurea L. | |
| Houstonia rubra Cav. | |
| Houstonia serpyllifolia Michx. | |
| Houstonia wrightii A.Gray |
| Houstonia caerulea L. | |
| Houstonia longifolia Gaertn. | |
| Houstonia purpurea L. | |
| Houstonia rubra Cav. | |
| Houstonia serpyllifolia Michx. | |
| Houstonia wrightii A.Gray |