Plants — K
- Kadsura heteroclita South-Asian kadsura
- Kadsura longipedunculata Long-stalk kadsura
- Kaempferia galanga Aromatic Ginger
- Kaempferia marginata
- Kaempferia rotunda Kaempferia
- Kalanchoe delagoensis
- Kalanchoe pinnata Air plant
- Kalmia latifolia Calico-bush
- Kalopanax septemlobus Castor aralia
- Kibatalia arborea
- Kielmeyera coriacea
- Kielmeyera variabilis
- Kigelia africana Bologna Sausage Tree
- Kleinhovia
- Knema angustifolia
- Knoxia roxburghii
- Koenigia alpina Alpine Knotweed
- Kopsia
- Kopsia arborea
- Kyllinga brevifolia Prickly short-leaf spikesedge