| Houstonia fasciculata A. Gray, 1882 |
| Houstonia fruticosa Rose, 1891 |
| Houstonia gracilis Brandegee, 1907 |
| Houstonia humifusa A. Gray, 1859 |
| Houstonia longiflora (Cav.) A. Gray, 1860 |
| Houstonia longipes S. Watson, 1883 |
| Houstonia macvaughii (Terrell) Govaerts ex Borhidi, 2012 |
| Houstonia mucronata (Benth.) B.L. Rob., 1910 |
| Houstonia mullerae (Fosberg) Terrell, 1979 |
| Houstonia nigricans (Lam.) Fernald, 1940 |
| Houstonia palmeri A. Gray, 1882 |
| Houstonia palmeri subsp. muzquizana (B.L. Turner) Borhidi, 2012 |
| 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 |