| Latin Name | Common Name | Family | Synonyms | Edibility Rating | Medicinal Rating |
| Actinidia kolomikta | Kiwi | Actinidiaceae | Kolomikta mandschurica. Regel. Trochostigma kolomikta. Rupr. | 4 | 0 |
| Aster yomena | | Asteraceae or Compositae | Kalimeris yomena. Kitam. | 1 | 0 |
| Carthamus lanatus | Distaff Thistle | Asteraceae or Compositae | Kentrophyllum lanatum. (L.)D.C. | 1 | 1 |
| Cedrelopsis grevei | Katrafay, Kathrafay | Rutaceae | Katafa crassisepalum Costantin & Poiss. | 2 | 4 |
| Euonymus latifolius | | Celastraceae | Kalonymus latifolius. (Mill.)Prokh. | 0 | 0 |
| Funtumia elastica | West African Rubber Tree. Lagos silk rubber | Apocynaceae | Kibatalia elastica (Preuss) Merr. Kixia elastica Preuss | 0 | 2 |
| Kadsura coccinea | | Schisandraceae | | 2 | 1 |
| Kadsura heteroclita | | Schisandraceae | | 2 | 0 |
| Kadsura japonica | | Schisandraceae | | 2 | 1 |
| Kadsura longepedunculata | | Schisandraceae | Kadsura peltigera. Rehd.&Wils. | 2 | 2 |
| Kadsura oblongifolia | | Schisandraceae | | 2 | 0 |
| Kalimeris incisa | | Asteraceae or Compositae | | 1 | 0 |
| Kalimeris laureana | | Asteraceae or Compositae | | 1 | 0 |
| Kalimeris pinnatifida | Japanese Aster | Asteraceae or Compositae | Aster cantoniensis. Boltonia cantoniensis. (Blume.)Franch.&Savat. | 1 | 0 |
| Kalmia angustifolia | Sheep Laurel | Ericaceae | | 0 | 2 |
| Kalmia latifolia | Mountain Laurel, Calico Bush, Ivy | Ericaceae | K. lucida. | 0 | 2 |
| Kalmia polifolia | Swamp Laurel, Bog laurel | Ericaceae | K. glauca. | 0 | 2 |
| Kalopanax sciadophylloides | | Araliaceae | Acanthopanax sciadophylloides. | 1 | 0 |
| Kalopanax septemlobus | Tree Aralia, Castor aralia | Araliaceae | K. pictus. (Thunb.)Nakai. K. ricinifolium. Acanthopanax ricinifolium. Acer pictum. Acer septemlobus. | 2 | 1 |
| Kerria japonica | Bachelor's Button, Japanese rose, Jew's Mallow, Japanese Kerria | Rosaceae | | 1 | 1 |
| Keteleeria davidiana | | Pinaceae | | 0 | 0 |
| Khaya anthotheca | White Mahogany, East African Mahogany | Meliaceae | Garretia anthotheca Welw. Khaya agboensis A.Chev. Khaya euryphylla Harms Khaya nyasica Stapf ex Bake | 0 | 2 |
| Khaya senegalensis | Dryzone Mahogany | Meliaceae | Swietenia senegalensis Desr. | 2 | 3 |
| Kickxia elatine | Fluellen, Sharpleaf cancerwort | Scrophulariaceae | Linaria elatine | 0 | 1 |
| Kinugasa japonica | Kinugasaso | Trilliaceae | Trillium japonicum. | 1 | 0 |
| Kirkophytum lyallii | | Araliaceae | Stilbocarpa lyallii. J.B.Armst. | 1 | 0 |
| Knautia arvensis | Field Scabious, Field scabiosa | Dipsacaceae | Scabiosa arvensis. | 0 | 2 |
| Knightia excelsa | Rewarewa | Proteaceae | | 1 | 0 |
| Kniphofia uvaria | Red Hot Poker , Common Torch Lily, Torch Lily, Poker Plant, Tritoma | Asphodelaceae | K. aloides. | 0 | 0 |
| Koeleria macrantha | June Grass, Prairie Junegrass | Poaceae or Gramineae | K. cristata. K. gracilis. K. pyramidata. Aira cristata. | 1 | 1 |
| Koelreuteria paniculata | Golden Rain Tree, Varnish Tree | Sapindaceae | | 2 | 1 |
| Kosteletzkya pentacarpos | | Malvaceae | | 3 | 0 |
| Kuhnia eupatorioides | | Asteraceae or Compositae | | 0 | 1 |
| Kummerowia stipulacea | Korean Lespedeza, Korean clover | Fabaceae or Leguminosae | Lespedeza stipulacea. Maxim. | 0 | 1 |
| Kummerowia striata | Common Lespedeza, Japanese clover | Fabaceae or Leguminosae | Hedysarum striatum. Lespedeza striata. (Thunb.)Hook.&Arn. | 2 | 1 |
| Kunzea muelleri | | Myrtaceae | | 1 | 1 |
| Kunzea pomifera | | Myrtaceae | | 1 | 0 |
| Leptospermum ericoides | | Myrtaceae | Kunzea ericoides. | 1 | 1 |
| Musa x paradisiaca | Banana | Musaceae | Karkandela × malabarica Raf. Musa × acutibracteata M.Hotta, Musa × alphurica Miq. Musa × aphurica Ru | 5 | 2 |
| Pycnanthemum albescens | Whiteleaf Mountain Mint | Lamiaceae or Labiatae | Koellia albescens (Torr.&Gray)Kuntze. | 0 | 1 |
| Pycnanthemum flexuosum | Mountain Mint, Appalachian mountainmint | Lamiaceae or Labiatae | Koellia flexuosa. | 1 | 2 |
| Pycnanthemum incanum | Hoary Mountain Mint | Lamiaceae or Labiatae | Koellia incana. | 1 | 2 |
| Pycnanthemum muticum | Cluster Mountain Mint | Lamiaceae or Labiatae | Koellia mutica. | 1 | 0 |
| Pycnanthemum pilosum | Mountain Mint, Whorled mountainmint | Lamiaceae or Labiatae | Koellia pilosa. | 2 | 0 |
| Pycnanthemum virginianum | Virginia Mountain Mint | Lamiaceae or Labiatae | Koellia virginiana. | 2 | 2 |
| Schisandra grandiflora | | Schisandraceae | Kadsura grandiflora. | 4 | 0 |
| Xyris caroliniana | Carolina Yelloweyed Grass | Xyridaceae | Kotsjiletti flexuosa. Ramotha floridana. Xyris canadensis. Xyris fimbriata. Xyris flexuosa. Xyris gl | 0 | 1 |