| Author | Title | Journal/publisher | Literature ref. no. |
| Verdcourt, B. (1988) | Rubiaceae, Part 1 | Flora Zambesiaca 5(1) | 188 |
Note that the process of capturing references from species to the literature and the reverse may be incomplete.
| Species found: 3 |
| Morinda angolensis |
| Psychotria eminiana var. eminiana |
| Richardia scabra |