| Aristida spadicea Kunth, 1815 |
| Aristida spanospicula Allred, Valdés-Reyna & Sánchez-Ken, 1995 |
| Aristida stricta Michx., 1803 |
| Aristida stricta var. decolorata E. Fourn. ex Dávila & Sánchez-Ken, 1994 |
| Aristida stricta var. grisebachiana E. Fourn. ex Dávila & Sánchez-Ken, 1994 |
| Aristida stricta var. nealleyi Vasey, 1890 |
| Aristida subbiflora Steud., 1855 |
| Aristida subuniflora Nash, 1903 |
| Aristida swartziana Steud., 1854 |
| Aristida tehuacanensis Sánchez-Ken & Dávila, 1994 |
| Aristida tenuifolia Hitchc., 1935 |
| Aristida tenuis (Kunth) Kunth, 1829 |
| Aristida tenuispica Hitchc., 1924 |
| Aristida ternipes Cav., 1799 |
| Aristida ternipes var. divergens (Vasey) Hitchc., 1924 |
| Aristida ternipes var. gentilis (Henrard) Allred, 1994 |
| Aristida ternipes var. minor (Vasey) Hitchc., 1933 |
| Aristida ternipes var. ternipes Cav., 1799 |
| Aristida tincta Trin. & Rupr., 1842 |
| Aristida tuitensis Sánchez-Ken & Dávila, 1995 |