| malar | The malar is the area at the sides of the chin.  | 
			
				| mandible | The mandible is the bill of the bird. | 
			
				| metamorphosis | In insects and amphibians, the transformation from immature to adult in two or more stages. | 
			
				| microsporangia | In Azolla ferns, the vary small structure which contains the spores. | 
			
				| monoecious | Having separate male and female flowers, but on the same plant. | 
			
				| mottling | to mark or diversify with spots or blotches of a different color or shade. | 
			
				| moustache | The moustache is a streak extending backwards and downwards from the base of the bill. | 
			
				| MRE | Missouri River Ecology  | 
			
				| mycelium | A mass of threadlike microscopic filaments (hyphae) comprising the fungus body. |