| maggot | the legless larva of Diptera. |
| membranous | parchment-like texture |
| midge | name for certain fly families. |
| midrib/midvein | the primary-rib or mid-vein of a leaf or leaflet. |
| mildew | a fungal disease of plants in which the mycelium and spores of the fungus are seen as a powdery or downy growth on the host surface. |
| mutation | something qualitatively new appearing abruptly without transitional forms or slow development; a sport; a potential species. |
| mycelia | several hyphae, perhaps a considerable mass of hyphae, that make up the vegetative body of a fungus. |
| mycelium | a hypha or mass of hyphae that make up the vegetative body of a fungus. |