| Orbexilum oliganthum (Brandegee) B.L. Turner, 2007 |
| Ormosia Jack., 1811 |
| Ormosia apulensis Cortés, 1919 |
| Ormosia carinata N. Zamora, 2006 |
| Ormosia chlorocalyx Ducke, 1944 |
| Ormosia coccinea (Aubl.) Jacks., 1811 |
| Ormosia isthmensis Standl., 1937 |
| Ormosia macrocalyx Ducke, 1922 |
| Ormosia macrophylla Benth., 1837 |
| Ormosia mexicana Standl., 1922 |
| Ormosia oaxacana Rudd, 1981 |
| Ormosia panamensis Benth. ex Seem., 1853 |
| Ormosia schippii Pierce ex Standl. & Steyerm., 1946 |
| Ormosia toledoana Standl., 1935 |
| Ormosia velutina Rudd, 1960 |
| Orobus L., 1753 |
| Orobus arborescens Sessé & Moc., 1889 |
| Orobus argenteus Mill., 1759 |
| Orobus diffusus Nutt., 1813 |
| Orobus dissitifolius Alef., 1861 |