Southeastern Arizona plant common names that begin with M.
- Macdougal's Nipple Cactus
- Machaeranthera, Arid
- Mala Mujer
- Mallow, Bristle
- Mallow, Cheeseweed
- Mallow, Creeping
- Mallow, Egyptian
- Mallow, Little
- Mallow, Small-flowered
- Mallow, Wheel
- Malta Starthistle
- Maltese Star-thistle
- Manroot, Gila
- Manyflowered Mentzelia
- Manzanita, Pointleaf
- Maple, Big-toothed
- Maple, Bigtooth
- Maple, Canyon
- Maple, Uvalde Big-tooth
- Maravilla
- Mare's Tail
- Marestail
- Marigold, Bur
- Mariola
- Mariposa Lily, Desert
- Mariposa Lily, Doubting
- Marsh Alkali Aster
- Marsh-pennywort, Floating
- Marshpennywort, Floating
- Matweed, Small
- Meadow Flax
- Melilot, Field
- Melilot, Ribbed
- Melon Loco
- Melon, Wright's
- Menodora, Rough
- Menodora, Yellow
- Mentzelia, Manyflowered
- Mesa Tansy-aster
- Mesa Tansyaster
- Mesquite Mistletoe
- Mesquite, Velvet
- Mexican Elder
- Mexican Gold Poppy
- Mexican Hat Plant
- Mexican Hat, Redspike
- Mexican Morningglory
- Mexican Palo Verde
- Mexican Paloverde
- Mexican Passion Flower
- Mexican Passionflower
- Mexican Poppy
- Mexican Sandbur
- Mexican Thistle
- Mexican-tea
- Midget Petunia
- Milkweed, Antelopehorn
- Milkweed, Arizona
- Milkweed, Butterfly
- Milkweed, Climbing
- Milkweed, Green-flowered
- Milkweed, Mojave
- Milkweed, Needle-Leaf
- Milkweed, Pine-Needle
- Milkweed, Pineneedle
- Milkweed, Spider
- Milkwort, Blue
- Milkwort, Broom
- Milkwort, Gland-leaf
- Milkwort, Glandleaf
- Milkwort, Purple
- Milkwort, Slenderlobe
- Milkwort, Velvetseed
- Milkwort, White
- Mimosa, Catclaw
- Mimosa, Velvet Pod
- Mimosa, Velvetpod
- Miner's Lettuce
- Miniature Lupine
- Miniature Wool Star
- Miniature Woollystar
- Miniature Woolstar
- Missouri Gourd
- Mist Flower
- Mistflower, Gregg's
- Mistflower, Palm-leaf
- Mistletoe, Big Leaf
- Mistletoe, Colorado Desert
- Mistletoe, Desert
- Mistletoe, Juniper
- Mistletoe, Mesquite
- Mistletoe, Pine Dwarf
- Mistletoe, Pineland Dwarf
- Mock Vervain, Dakota
- Mock Vervain, Southwestern
- Modiola, Carolina
- Mojave Desertstar
- Mojave Lupine
- Mojave Milkweed
- Mojave Spurge
- Monkey Flower, Common
- Monkey Flower, Crimson
- Monkey Flower, Pygmy
- Monkey-flower, Cardinal
- Monkey-flower, False
- Monkey-flower, Redstem
- Monkeyflower, Common
- Monkeyflower, False
- Monkeyflower, Little Redstem
- Monkeyflower, Red
- Monkeyflower, Scarlet
- Monkeyflower, Seep
- Mono Ragwort
- Monsterwort, Annual
- Mormon Tea, Longleaf
- Morning Glory, Bird's Foot
- Morning Glory, Canyon
- Morning Glory, Crestrib
- Morning Glory, Ivy-leaved
- Morning Glory, Ivyleaf
- Morning Glory, Smallflowered
- Morning Glory, Trans-Pecos
- Morning-glory, Canyon
- Morning-glory, Crestrib
- Morning-glory, Ivyleaf
- Morning-glory, Trans-Pecos
- Morning-glory, Transpecos
- Morning-glory, Tripleleaf
- Morning-glory, Woolly
- Morningglory, Entireleaf
- Morningglory, Mexican
- Morningglory, Perennial
- Moroccan Toadflax
- Mountain Gromwell
- Mountain Parsley
- Mountain Rose
- Mountain Stickleaf
- Mountain Yucca
- Mule-fat
- Mule's Fat
- Mullein, Common
- Mullein, Flannel
- Mullein, Great
- Mullein, Woolly
- Musk Mustard
- Mustard Evening Primrose
- Mustard, Asian
- Mustard, Beanpodded
- Mustard, Bladderpod
- Mustard, Blue
- Mustard, California
- Mustard, Lacepod
- Mustard, Musk
- Mustard, Purple
- Mustard, Rock
- Mustard, Rocket
- Mustard, Sahara
- Mustard, Slimleaf Plains
- Mustard, Tenella