Science magazines
- Mat-forming Quillwort
- Maui Parrotbill
- Maui Remya
- Mauna Kea Silversword
- McDonald's Rock-cress
- Mead's Milkweed
- Mehamehame
- Menzies' Wallflower
- Merriam's Montezuma Quail
- Mesa Verde Cactus
- Metcalf Canyon Jewelflower
- Mexican Blindcat
- Mexican Flannelbush
- Mexican Gray Wolf
- Mexican Long-nosed Bat
- Mexican Spotted Owl
- Miccosukee Gooseberry
- Michaux's Sumac
- Michigan Monkey-flower
- Micronesian Megapode