| Koanophyllon sorensenii R.M. King & H. Rob., 1972 |
| Koanophyllon standleyi (B.L. Rob.) R.M. King & H. Rob., 1971 |
| Koanophyllon tripartitum B.L. Turner, 1987 |
| Krigia Schreb., 1791 |
| Krigia cespitosa (Raf.) K.L. Chambers, 1973 |
| Krigia wrightii (A. Gray) K.L. Chambers ex K.J. Kim, 1992 |
| Kuhnia L., 1763 |
| Kuhnia adenolepis B.L. Rob., 1911 |
| Kuhnia chlorolepis Woot. & Standl., 1913 |
| Kuhnia eupatorioides L., 1763 |
| Kuhnia eupatorioides var. chlorolepis (Wooton & Standl.) Cronquist, 1994 |
| Kuhnia eupatorioides var. gracillima A. Gray, 1850 |
| Kuhnia leptophylla Scheele, 1848 |
| Kuhnia leptophylla var. mexicana Scheele, 1946 |
| Kuhnia microphylla Shinners, 1946 |
| Kuhnia oreithales B.L. Rob., 1918 |
| Kuhnia rosmarinifolia Vent., 1803 |
| Kuhnia rosmarinifolia var. chlorolepis (Wooton & Standl.) S.F. Blake, 1940 |
| Kuhnia rosmarinifolia var. gracillima (A. Gray) Blank., 1907 |
| Kuhnia schaffneri A. Gray, 1882 |