| Senna racemosa var. racemosa (Mill.) H.S. Irwin & Barneby, 1982 |
| Senna racemosa var. sororia H.S. Irwin & Barneby, 1982 |
| Senna reticulata (Willd.) H.S. Irwin & Barneby, 1982 |
| Senna ripleyana (H.S. Irwin & Barneby) H.S. Irwin & Barneby, 1979 |
| Senna roemeriana (Scheele) H.S. Irwin & Barneby, 1982 |
| Senna septemtrionalis (Viv.) H.S. Irwin & Barneby, 1982 |
| Senna siamea (Lam.) H.S. Irwin & Barneby, 1982 |
| Senna skinneri (Benth.) H.S. Irwin & Barneby, 1982 |
| Senna sousana H.S. Irwin & Barneby, 1982 |
| Senna spectabilis (DC.) H.S. Irwin & Barneby, 1982 |
| Senna spectabilis var. spectabilis (DC.) H.S. Irwin & Barneby, 1982 |
| Senna talpana H.S. Irwin & Barneby, 1982 |
| Senna tomentosa Batka, 1854 |
| Senna tonduzii (Standl.) H.S. Irwin & Barneby, 1982 |
| Senna toroides Roxb., 1832 |
| Senna undulata (Benth.) H.S. Irwin & Barneby, 1982 |
| Senna uniflora (Mill.) H.S. Irwin & Barneby, 1982 |
| Senna unijuga (Rose) H.S. Irwin & Barneby, 1982 |
| Senna villosa (Mill.) H.S. Irwin & Barneby, 1982 |
| Senna wislizeni (A. Gray) H.S. Irwin & Barneby, 1979 |