| 1 | Aristida | adscensionis | Sixweeks Threeawn | Grasses | Poaceae | Magnoliopsida |
| 2 | Aristida | dichotoma | Churchmouse Threeawn | Grasses | Poaceae | Magnoliopsida |
| 3 | Aristida | dichotoma var. curtissii | Churchmouse Threeawn (curtissii) | Grasses | Poaceae | Magnoliopsida |
| 4 | Aristida | dichotoma var. dichotoma | Churchmouse Threeawn (dichotoma) | Grasses | Poaceae | Magnoliopsida |
| 5 | Aristida | lanosa | Woolly Threeawn | Grasses | Poaceae | Magnoliopsida |
| 6 | Aristida | longespica | Slim-spiked Threeawn | Grasses | Poaceae | Magnoliopsida |
| 7 | Aristida | longespica var. geniculata | Slim-spiked Threeawn (geniculata) | Grasses | Poaceae | Magnoliopsida |
| 8 | Aristida | longespica var. longespica | Slim-spiked Threeawn (longispica) | Grasses | Poaceae | Magnoliopsida |
| 9 | Aristida | oligantha | Prairie Threeawn | Grasses | Poaceae | Magnoliopsida |
| 10 | Aristida | purpurascens | Arrow-feather Threeawn | Grasses | Poaceae | Magnoliopsida |
| 11 | Aristida | tuberculosa | Seaside Threeawn | Grasses | Poaceae | Magnoliopsida |
| 12 | Aristida | virgata | Wand-like Threeawn | Grasses | Poaceae | Magnoliopsida |