| Houstonia prostrata Brandegee, 1901 |
| Houstonia rubra Cav., 1799 |
| Houstonia sharpii Terrell, 1980 |
| Houstonia spellenbergii (G.L. Nesom & Vorobik) Terrell, 1991 |
| Houstonia teretifolia Terrell, 1979 |
| Houstonia umbratilis (B.L. Rob.) Terrell, 1910 |
| Houstonia wrightii A. Gray, 1882 |
| Houstonia xestosperma (B.L. Rob. & Greenm.) Terrell, 1980 |
| Isertia Schreb., 1789 |
| Isertia deamii Bartlett, 1907 |
| Isertia haenkeana DC., 1830 |
| Isertieae A. Rich., 1830 |
| Ixora L., 1753 |
| Ixora acuminata Roxb., 1820 |
| Ixora americana Jacq., 1798 |
| Ixora coccinea L., 1753 |
| Ixora finlaysoniana Wall. ex G. Don, 1834 |
| Ixora floribunda (A. Rich.) Griseb., 1866 |
| Ixora occidentalis L., 1759 |
| Ixoreae A. Gray, 1858 |