| TaxonId | Name | Volume | Year | ||
| 200016507 | Rhododendron oldhamii | 砖红杜鹃 | Vol.14 | 2005 | |
| 242344242 | Rhododendron oldhamii var. glandulosum | Vol.14 | 2005 | ||
| 200016508 | Rhododendron oleifolium | Vol.14 | 2005 | ||
| 242344243 | Rhododendron oligocarpum | 稀果杜鹃 | Vol.14 | 2005 | |
| 242445953 | Rhododendron ombrochares | Vol.14 | 2005 | ||
| 200016509 | Rhododendron openshawianum | Vol.14 | 2005 | ||
| 242444878 | Rhododendron oporinum | Vol.14 | 2005 | ||
| 200016510 | Rhododendron orbiculare | 团叶杜鹃 | Vol.14 | 2005 | |
| 242344245 | Rhododendron orbiculare subsp. cardiobasis | 心基杜鹃 | Vol.14 | 2005 | |
| 242344247 | Rhododendron orbiculare subsp. oblongum | 长圆团叶杜鹃 | Vol.14 | 2005 | |
| 242344248 | Rhododendron orbiculare subsp. orbiculare | 团叶杜鹃(原亚种) | Vol.14 | 2005 | |
| 242344249 | Rhododendron oreinum | Vol.14 | 2005 | ||
| 200016511 | Rhododendron oreodoxa | 山光杜鹃 | Vol.14 | 2005 | |
| 242344250 | Rhododendron oreodoxa var. adenostylosum | 腺柱山光杜鹃 | Vol.14 | 2005 | |
| 242344251 | Rhododendron oreodoxa var. fargesii | 粉红杜鹃 | Vol.14 | 2005 |
