Jersey Cudweed 
Jerusalem Artichoke 
Jurinea mollis 
Jurinea staehelinae 
Kenikir 
Kidney-leaf Rosinweed 
Klasea cerinthifolia 
Klasea pusilla 
Kleinia neriifolia 
Koelpinia linearis 
Korean Dandelion 
Korean Dandelion 
Lachnophyllum noeanum 
Lactuca aculeata 
Lactuca hispida 
Lactuca orientalis 
Lactuca tuberosa 
Lactuca undulata 
Lacy Ragweed 
Lance-leaved coreopsis 
Large-flowered mat daisy 
Large-flowered tickseed 
Large-leaved Aster 
Lasiocephalus ovatus