| Polyclathra longipedunculata (Cogn.) C. Jeffrey, 1971 |
| Poppya Neck. ex M. Roem., 1846 |
| Poppya operculata (L.) Roem., 1846 |
| Posadaea Cogn., 1890 |
| Posadaea sphaerocarpa Cogn., 1890 |
| Psiguria Neck. ex Arn., 1841 |
| Psiguria bignoniacea (Poepp. & Endl.) Wunderlin, 1978 |
| Psiguria longipedunculata (Cogn.) Wunderlin, 1978 |
| Psiguria triphylla (Miq.) C. Jeffrey, 1978 |
| Psiguria warscewiczii (Hook. f.) Wunderlin, 1978 |
| Pteropepon (Cogn.) Cogn., 1916 |
| Pterosicyos Brandegee, 1914 |
| Pterosicyos laciniatus Brandegee, 1914 |
| Ranugia Post & Kuntze, 1903 |
| Raphanistrocarpus (Baill.) Pax, 1889 |
| Raphanocarpus Hook. f., 1871 |
| Roseanthus Cogn., 1896 |
| Roseanthus albiflorus Cogn., 1896 |
| Roseanthus elongatus Rose, 1905 |
| Roseanthus heterophyllus Brandegee, 1922 |