Index of plants by genus
| Species | Common Name | Family |
| Maclura pomifera | Osage Orange | Moraceae |
| Magnolia acuminata | Cucumber Magnolia | Magnoliaceae |
| Magnolia grandiflora | Southern Magnolia | Magnoliaceae |
| Magnolia fraseri | Mountain Magnolia | Magnoliaceae |
| Maianthemum canadense | Canada Mayflower | Liliaceae |
| Maianthemum racemosum | Feathery False Solomon's Seal | Liliaceae |
| Maianthemum stellatum | Starry False Solomon's Seal | Liliaceae |
| Maianthemum trifolium | Three-leaved False Solomon's Seal | Liliaceae |
| Malus coronaria | Sweet Crab Apple | Rosaceae |
| Marchantia polymorpha | Common Liverwort | Marchantiaceae |
| Matteuccia struthiopteris | Ostrich Fern | Dryopteridaceae |
| Medeola virginiana | Indian Cucumber Root | Liliaceae |
| Melampyrum lineare | Cow-wheat | Orobanchaceae |
| Menispermum canadense | Common Moonseed | Menispermaceae |
| Mentha arvensis var. villosa | Wild Mint | Lamiaceae |
| Mertensia virginica | Virginia Bluebells | Boraginaceae |
| Mikania scandens | Climbing Hempvine | Asteraceae |
| Mimulus glabratus var. jamesii | Yellow Monkey Flower | Scrophulariaceae |
| Mimulus moschatus | Muskflower | Scrophulariaceae |
| Mimulus ringens | Allegheny Monkey Flower | Scrophulariaceae |
| Mitchella repens | Partidgeberry | Rubiaceae |
| Mitella diphylla | Two-leaved Mitrewort | Saxifragaceae |
| Mitella nuda | Naked Mitrewort | Saxifragaceae |
| Mnium punctatum | Dotted Mnium | Mniaceae |
| Monarda bradburiana | Bradbury's Monarda | Lamiaceae |
| Monarda clinopodia | Basil Bee Balm | Lamiaceae |
| Monarda didyma | Oswego Tea | Lamiaceae |
| Monarda fistulosa | Wild Bergamot | Lamiaceae |
| Monarda punctata | Horse Mint | Lamiaceae |
| Monotropa uniflora | Indian Pipe | Ericaceae |
| Morella pensylvanica | Northern Bayberry | Myricaceae |
| Morus rubra | Red Mulberry | Moraceae |
| Myrica gale | Sweetgale | Myricaceae |
© 2004 Michael Hough