| Justicia campechiana subsp. campechiana Standl. ex Lundell, 1934 |
| Justicia canbyi Greenm., 1904 |
| Justicia candelariae (Oerst.) Leonard, 1936 |
| Justicia candicans (Nees) L.D. Benson, 1981 |
| Justicia carnea Lindl., 1831 |
| Justicia carthagenensis Jacq., 1760 |
| Justicia caudata A. Gray, 1886 |
| Justicia chiapensis Brandegee, 1914 |
| Justicia chimalapensis T.F. Daniel, 1999 |
| Justicia chlorostachya Leonard, 1958 |
| Justicia chol T.F. Daniel, 1995 |
| Justicia clinopodium A. Gray ex Greenm., 1897 |
| Justicia coahuilana T.F. Daniel, 1980 |
| Justicia cobensis Lundell, 1941 |
| Justicia coccinea Cav., 1794 |
| Justicia colorifera V.A.W. Graham, 1988 |
| Justicia comata (L.) Lam., 1785 |
| Justicia corymbulosa Bertol., 1840 |
| Justicia corynimorpha D.N. Gibson, 1972 |
| Justicia cuicatlana T.F. Daniel, 1998 |