Plants: M
- Macadamia Macadamia integrifolia Nut
- Macedonian Scabious Knautia macedonica Garden perennial
- Mache Valerianella locusta Leafy
- Macrantha Pearlbush Exochorda × macrantha Flowering shrub
- Madagascar Jasmine Stephanotis floribunda Vine
- Madagascar Periwinkle Catharanthus roseus Garden perennial
- Madonna Lily Lilium candidum
- Mahala Mat Ceanothus prostratus Low shrub
- Maiden Pink Dianthus deltoides Creeping perennial
- Maidenhair Fern Adiantum pedatum Fern
- Malabar Spinach Basella alba Leafy
- Mallow Ninebark Physocarpus malvaceus Flowering shrub
- Malope Malope trifida Garden annual
- Maltese Cross Lychnis chalcedonica Garden perennial
- Manchurian Lilac Syringa pubescens subsp. patula Flowering shrub
- Mandevilla Mandevilla × amoena
- Mango Mangifera indica Tree fruit
- Manila Grass Zoysia matrella Grass
- Mapleleaf Viburnum Viburnum acerifolium Flowering shrub
- Marginal Wood Fern Dryopteris marginalis Fern
- Marguerite Daisy Argyranthemum frutescens Garden perennial
- Marionberry Rubus ursinus Berry
- Maritime Ceanothus Ceanothus maritimus Low shrub
- Marjoram Origanum majorana Herb
- Marmalade Bush Streptosolen jamesonii Flowering shrub
- Marsh Mallow Althaea officinalis Wildflower
- Marsh Marigold Caltha palustris Garden perennial
- Martagon Lily Lilium martagon Garden perennial
- Maryland Goldenaster Chrysopsis mariana Wildflower
- Maryland Meadowbeauty Rhexia mariana Wildflower
- Maryland Senna Senna marilandica Wildflower
- Mascarene Grass Zoysia tenuifolia Creeping perennial
- Masterwort Astrantia major Garden perennial
- Mat Penstemon Penstemon caespitosus Creeping perennial
- Matilija Poppy Romneya coulteri Wildflower
- Maximilian Sunflower Helianthus maximiliani Wildflower
- Mayapple Podophyllum peltatum Creeping perennial
- Mayhaw Crataegus aestivalis Tree fruit
- Maypop Passiflora incarnata Fruiting
- Meadow Blazing Star Liatris ligulistylis Wildflower
- Meadow Checkerbloom Sidalcea campestris Wildflower
- Meadow Cranesbill Geranium pratense Garden perennial
- Meadow Phlox Phlox maculata Garden perennial
- Meadow Sage Salvia pratensis Wildflower
- Meadowfoam Limnanthes douglasii Garden annual
- Meadowsweet Filipendula ulmaria Wildflower
- Mealycup Sage Salvia farinacea Garden perennial
- Mediterranean Spurge Euphorbia characias Flowering shrub
- Medlar Mespilus germanica Tree fruit
- Meehan's Mint Meehania cordata Creeping perennial
- Melon Cucumis melo Fruiting
- Memorial Rose Rosa wichuraiana Flowering shrub
- Mexican Buckeye Ungnadia speciosa Flowering shrub
- Mexican Bush Sage Salvia leucantha Garden perennial
- Mexican Flame Vine Pseudogynoxys chenopodioides Vine
- Mexican Fleabane Erigeron karvinskianus Creeping perennial
- Mexican Giant Hyssop Agastache mexicana Garden perennial
- Mexican Hat Ratibida columnifera Wildflower
- Mexican Heather Cuphea hyssopifolia Flowering shrub
- Mexican Honeysuckle Justicia spicigera Flowering shrub
- Mexican Mint Marigold Tagetes lucida Herb
- Mexican Orange Choisya ternata Flowering shrub
- Mexican Pink Silene laciniata Wildflower
- Mexican Plum Prunus mexicana Tree fruit
- Mexican Stonecrop Sedum mexicanum Creeping perennial
- Mexican Sunflower Tithonia rotundifolia Garden annual
- Mexican Tulip Poppy Hunnemannia fumariifolia Garden perennial
- Mexican Whorled Milkweed Asclepias fascicularis Wildflower
- Meyer Lemon Citrus x meyeri Tree fruit
- Meyer Lilac Syringa meyeri Flowering shrub
- Miami Mist Phacelia purshii
- Michael's Flower Fritillaria michailovskyi Bulb
- Michigan Lily Lilium michiganense Wildflower
- Milky Bellflower Gadellia lactiflora Wildflower
- Millet Panicum miliaceum Grain
- Miner's Lettuce Claytonia perfoliata Leafy
- Miniature Lupine Lupinus bicolor Wildflower
- Mint Mentha spicata Herb
- Miss Willmott's Ghost Eryngium giganteum Wildflower
- Missouri Evening Primrose Oenothera macrocarpa Creeping perennial
- Missouri Goldenrod Solidago missouriensis Wildflower
- Mizuna Brassica rapa var. japonica Leafy
- Mondo Grass Ophiopogon japonicus Creeping perennial
- Monkshood Aconitum napellus Garden perennial
- Montbretia Crocosmia × crocosmiiflora Garden perennial
- Monterey Manzanita Arctostaphylos hookeri Low shrub
- Moonflower Ipomoea alba Vine
- Morning Glory Ipomoea purpurea Garden annual
- Moroccan Toadflax Linaria maroccana Garden annual
- Moss Campion Silene acaulis Moss like
- Moss Rose Portulaca grandiflora Garden annual
- Moss Verbena Glandularia pulchella Creeping perennial
- Mossy Saxifrage Saxifraga × arendsii Creeping perennial
- Mottled Wild Ginger Hexastylis shuttleworthii Creeping perennial
- Mount Lemmon Marigold Tagetes lemmonii Flowering shrub
- Mountain Alyssum Alyssum montanum Creeping perennial
- Mountain Avens Dryas octopetala Low shrub
- Mountain Everlasting Antennaria dioica Creeping perennial
- Mountain Fleece Persicaria amplexicaulis Garden perennial
- Mountain Goldenbanner Thermopsis montana Wildflower
- Mountain Hydrangea Hydrangea serrata Flowering shrub
- Mountain Laurel Kalmia latifolia Flowering shrub
- Mountain Monardella Monardella odoratissima Wildflower
- Mountain Pieris Pieris floribunda Flowering shrub
- Mountain Sandwort Arenaria montana Creeping perennial
- Mouse-Ear Tickseed Coreopsis auriculata Wildflower
- Moyes Rose Rosa moyesii Flowering shrub
- Mulberry Morus alba Tree fruit
- Mule Fat Baccharis salicifolia Flowering shrub
- Mule's Ears Wyethia amplexicaulis Wildflower
- Mung Beans Vigna radiata Legume
- Munro's Globemallow Sphaeralcea munroana Wildflower
- Murray's Penstemon Penstemon murrayanus
- Muscadine Grape Vitis rotundifolia Berry
- Musk Mallow Malva moschata Garden perennial
- Musk Rose Rosa moschata Flowering shrub
- Mustard Brassica juncea Brassica