| Indigofera pohliana Benth., 1839 |
| Indigofera pueblensis Rydb., 1923 |
| Indigofera purpusii Brandegee, 1919 |
| Indigofera rosei Rydb., 1923 |
| Indigofera sabulicola Benth., 1859 |
| Indigofera salmoniflora Rose, 1897 |
| Indigofera sinaloensis M. Sousa & Cruz Durán, 2017 |
| Indigofera sousae Rzed. & R. Grether, 2018 |
| Indigofera sphaerocarpa A. Gray, 1853 |
| Indigofera sphenoides Rydb., 1923 |
| Indigofera sphinctosperma Standl., 1919 |
| Indigofera spicata Forssk., 1775 |
| Indigofera suffruticosa Mill., 1768 |
| Indigofera texana Buckley, 1862 |
| Indigofera thibaudiana DC., 1825 |
| Indigofera tinctoria L., 1753 |
| Indigofera tinctoria var. brachycarpa DC., 1825 |
| Indigofera torulosa Hook. & Arn., 1838 |
| Indigofera trita L. f., 1782 |
| Indigofera trita subsp. scabra (Roth) de Kort & G. Thijsse, 1984 |