| Piper claudicans Trel., 1936 |
| Piper cobanense Trel., 1931 |
| Piper cobanense var. sarculatum Trel., 1929 |
| Piper coilostachyum C. DC., 1892 |
| Piper colaphitolerans Trel., 1937 |
| Piper colipanum C. DC., 1872 |
| Piper colonense C. DC., 1920 |
| Piper colotlipanense Bornst., 1989 |
| Piper commutatum Steud., 1841 |
| Piper concepcionis Trel., 1929 |
| Piper concinnum Haw., 1821 |
| Piper cordillerianum C. DC., 1869 |
| Piper cordoncillo Trel., 1929 |
| Piper cordoncillo var. apazoteanum Trel., 1929 |
| Piper cordovanum C. DC., 1869 |
| Piper cordulatum C. DC., 1866 |
| Piper corrugatum Kuntze, 1891 |
| Piper crassinervium Kunth, 1816 |
| Piper cubilquitzianum C. DC., 1920 |
| Piper curtirachis W.C. Burger, 1971 |