| Kalmia carolina Small | map | |
| Kalmia cuneata Michx. | map | |
| Kalmia hirsuta Walt. | map | |
| Kalmia latifolia L. | map | images (1) (2) (3) |
| Kickxia elatine (L.) Dumort. | map | |
| Kochia scoparia (L.) Schrad. | map | |
| Kosteletzkya virginica (L.) K. Presl ex Gray | map | images (1) |
| Krigia cespitosa (Raf.) Chambers | map | |
| Krigia dandelion (L.) Nutt. | map | |
| Krigia montana (Michx.) Nutt. | map | |
| Krigia virginica (L.) Willd. | map | images (1) (2) |
| Kummerowia stipulacea (Maxim.) Makino | map | |
| Kummerowia striata (Thunb.) Schindl. | map | |
| Kyllinga brevifolia Rottb. | map | |
| Kyllinga gracillima Miq. | map | |
| Kyllinga odorata Vahl | map | images (1) |
| Kyllinga pumila Michx. | map | images (1) (2) |