| Name | Children | Media (from resource) | Traits |
|---|---|---|---|
| Unionidae (unionid freshwater mussels) | 5 | 0 | 0 |
| Unionoida | 1 | 0 | 0 |
| Upupa Linnaeus 1758 | 1 | 0 | 0 |
| Upupa epops Linnaeus 1758 (Common Hoopoe) | 0 | 0 | 1 |
| Upupidae (hoopoes) | 1 | 0 | 0 |
| Uraria (uraria) | 1 | 0 | 0 |
| Uraria crinita (L.) DC. (Asian foxtail) | 0 | 0 | 1 |
| Urceola | 2 | 0 | 0 |
| Urceola micrantha (Wall. ex G. Don) D. J. Middleton | 0 | 0 | 1 |
| Urceola minutiflora (Pierre) D. J. Middleton | 0 | 0 | 1 |
| Urena (urena) | 3 | 0 | 0 |
| Urena lobata L. (Caesarweed) | 0 | 0 | 1 |
| Urena repanda Roxb. | 0 | 0 | 1 |
| Urena repanda Roxb. | 0 | 0 | 1 |
| Urocissa Cabanis 1851 | 1 | 0 | 0 |
