Maltese Star-Thistle 
Manzanilla loca 
Marguerite Daisy 
Maryland golden-aster 
Meadow Hawkweed 
Meadow salsify 
Mediterranean Cat's-Ear 
Mediterranean Marigold 
Mediterranean Phagnalon 
Melampodium leucanthum 
Melancholy Thistle 
Menyanthes 
Mexican marigold 
Mexican Sunflower 
Michauxia laevigata 
Micropus supinus 
Milk thistle 
Monopsis stellarioides 
Monticalia vernicosa 
Moth daisy-bush 
Mountain bluet 
Mountain dandelion 
Mountain lettuce 
Mountain little sunflower