Mexican Hedge Nettle 
Mexican Petunia 
Micromeria serbaliana 
Milky emu bush 
Mimulus lewisii 
Miniature Beefsteak-Plant 
Minnieroot 
Monardella odoratissima 
Monophyllaea glauca (One-leaf plant) 
Monopyle uniflora 
Monte Gargano Dead-Nettle 
Monterey Indian Paintbrush 
Mosheovia galilaea 
Moth mullein 
Mother of Thyme 
Motherwort 
Mountain foxglove 
Mountain Indian paintbrush 
Mountain owl's-clover 
Mountain Thistle 
Mulberry-waved 
Musk Deadnettle 
Musk Monkeyflower 
Myoporum laetum