Common names: M
- Maack's spindle tree
- mabolo
- mace sedge
- Macedonian widow flower
- Madagascar dragon tree
- Madagascar palm
- Madagascar periwinkle
- madder
- Madeira lavender
- Madeiran cranesbill
- Madeiran orchid
- madonna lily
- madwort
- magnolia
- mahaleb cherry
- maiden pink
- maidenhair fern
- maidenhair spleenwort
- maidenhair tree
- Majorcan hellebore
- Majorcan peony
- malabar spinach
- Malayian spindle tree
- male fern
- malevolence
- malling toadflax
- Mallorca foxglove
- mallow
- mallow bindweed
- Maltese cross
- malva nut tree
- Manchurian catalpa
- Manchurian clematis
- Manchurian dutchman's pipe
- Manchurian indigo
- Manchurian lilac
- Manchurian monkshood
- Manchurian spikenard
- Manchurian striped maple
- mandarin
- mandarine
- mangel
- mango
- mango tree
- mangold
- mangrove
- mangrove fan palm
- manioc
- manna ash
- many-flowered cotoneaster
- many-lobed groundsel
- many-lobed ragwort
- manyflower currant
- maple
- mare's tail
- marguerite
- Marian thistle
- marigold
- marijuana
- maritime sunburst lichen
- marjoram
- marsh betony
- marsh gladiolus
- marsh helleborine
- marsh Labrador tea
- marsh mallow
- marsh marigold
- marsh orchid
- marsh rosemary
- marsh samphire
- marsh spurge
- marsh woundwort
- marshpepper knotweed
- marvel of Peru
- Maryland meadowbeauty
- masterwort
- mastic tree
- matatabi
- Mauritius thorn
- May lily
- mayapple
- maypop
- meadow beard tongue
- meadow blazing star
- meadow buttercup
- meadow clary
- meadow cranesbill
- meadow deathcamas
- meadow geranium
- meadow hawkweed
- meadow phlox
- meadow rue
- meadow salsify
- meadow squill
- meadow sweet
- mealy sage
- mealycup sage
- Mediterranean beach daisy
- Mediterranean cypress
- Mediterranean dwarf palm
- medlar
- melancholy thistle
- melic
- melilot
- melon
- mercury
- Metternich's rhododendron
- Mexican aster
- Mexican bush sage
- Mexican cliffrose
- Mexican creeping zinnia
- Mexican fan palm
- Mexican feather grass
- Mexican flannelbush
- Mexican giant cardon
- Mexican giant hyssop
- Mexican lobelia
- Mexican marigold
- Mexican mock orange
- Mexican morning glory
- Mexican orange blossom
- Mexican prickly poppy
- Mexican shell flower
- Mexican snow ball
- Mexican sunflower
- Mexican tulip poppy
- Mexican twist
- Mexican viper
- mezereon
- miagos bush
- Michaelmas daisy
- Mickey Mouse plant
- midday flower
- midland hawthorn
- mignonette
- military orchid
- milkweed
- milkwort
- milky bellflower
- millet
- miniature date palm
- Minorca honeysuckle
- mint
- mint bush
- mintbush
- mintleaf bee balm
- mirabelle
- Mishchenko squill
- Missouri evening primrose
- mist flower
- mistery flower
- mistletoe
- mock cypress
- mock orange
- Modjadji cycad
- monarch birch
- monastery bells
- money tree
- Mongolian clematis
- Mongolian deutzia
- monkey flower
- monkey plant
- monkey pod tree
- monkey-bread tree
- monkshood
- montbretia
- Monterey cypress
- Montpelier rock rose
- moon daisy
- moon flower
- moonbeam tickseed
- moonseed
- moor birch
- Mormon tea
- morning glory
- Morrow's sedge
- mosaic puffball
- moschata rose
- mosquito grass
- moss campion
- moss fern
- moss phlox
- moss-rose purslane
- mossy saxifrage
- mossy stonecrop
- moth mullein
- mother of thousands
- mother spleenwort
- mother-in-law's tongue
- motherwort
- mottled dutchman's pipe
- Mount Omei rose
- mountain aloe
- mountain arnica
- mountain ash
- mountain avens
- Mountain avens
- mountain cherry
- mountain cowslip
- mountain cranberry
- mountain deathcamas
- mountain devil
- mountain fleece
- mountain hydrangea
- mountain kidney vetch
- mountain knapweed
- mountain laurel
- mountain mint
- mountain peppergrass
- mountain pepperweed
- mountain rose bay
- mountain scabious
- mountain sedge
- mountain silverbell
- mountain spinach
- mountain trumpet
- mouse garlic
- mouse-ear chickweed
- moyesii rose
- mulberry
- mullein
- multiflora rose
- multiflowering tulip
- musk
- musk mallow
- musk maple
- musk rose
- musk thistle
- mustard
- myrtle
- myrtle beech
- myrtle-leaf milkwort
- Mysore raspberry
- Mysore thorn