| Author | Title | Journal/publisher | Literature ref. no. |
| van der Walt, R. (2009) | Wild Flowers of the Limpopo Valley | Retha van der Walt, Musina, South Africa | 963 |
Note that the process of capturing references from species to the literature and the reverse may be incomplete.
| Species found: 4 |
| Argemone mexicana |
| Pegolettia senegalensis |
| Plumbago zeylanica |
| Portulaca quadrifida |