| Symbol | Scientific name | Common name/Accepted name (for synonyms) | Family |
| MACHC | Matricaria chamomilla L. var. coronata (J. Gay) Coss. & Germ. | Matricaria recutita | Asteraceae
|
| MACH2 | Matricaria chamomilla L. 1755 & 1763, non 1753 | Matricaria recutita | Asteraceae
|
| MACO7 | Matricaria courrantiana DC. | crown mayweed | Asteraceae
|
| MADI6 | Matricaria discoidea DC. | disc mayweed | Asteraceae
|
| MAGL13 | Matricaria globifera (Thunb.) Fenzl ex Harv. | Oncosiphon piluliferum | Asteraceae
|
| MAGR13 | Matricaria grandiflora (Hook.) Britt. | Tripleurospermum maritima ssp. phaeocephala | Asteraceae
|
| MAHO2 | Matricaria hookeri (Schultz-Bip.) Czern. | Tripleurospermum maritima ssp. phaeocephala | Asteraceae
|
| MAIN12 | Matricaria inodora L. | Tripleurospermum perforata | Asteraceae
|
| MAMAI | Matricaria maritima L. ssp. inodora (L.) Clapham | Tripleurospermum perforata | Asteraceae
|
| MAMAP | Matricaria maritima L. ssp. phaeocephala (Rupr.) Rauschert | Tripleurospermum maritima ssp. phaeocephala | Asteraceae
|
| MAMAA | Matricaria maritima L. var. agrestis (Knaf) Wilmott | Tripleurospermum perforata | Asteraceae
|
| MAMAN | Matricaria maritima L. var. nana (Hook.) Boivin | Tripleurospermum maritima ssp. phaeocephala | Asteraceae
|
| MAMA10 | Matricaria maritima L. | Tripleurospermum maritima ssp. maritima | Asteraceae
|
| MAMA11 | Matricaria matricarioides auct. non (Less.) Porter | Matricaria discoidea | Asteraceae
|
| MAOC | Matricaria occidentalis Greene | valley mayweed | Asteraceae
|
| MAPA18 | Matricaria parthenium L. | Tanacetum parthenium | Asteraceae
|
| MAPE2 | Matricaria perforata M�rat | Tripleurospermum perforata | Asteraceae
|
| MAPR5 | Matricaria prostrata Sw. | Egletes prostrata | Asteraceae
|
| MARE6 | Matricaria recutita L. | German chamomile | Asteraceae
|
| MASU9 | Matricaria suaveolens (Pursh) Buch., non L. | Matricaria discoidea | Asteraceae
|
| MASU8 | Matricaria suaveolens L. | Matricaria recutita | Asteraceae
|
| MASU4 | Matricaria suffruticosa (L.) Druce | Oncosiphon suffruticosum | Asteraceae
|
| MATRI | Matricaria L. | mayweed | Asteraceae
|
| MAPE4 | Matteuccia pensylvanica (Willd.) Raymond | Matteuccia struthiopteris | Dryopteridaceae
|
| MASTP | Matteuccia struthiopteris (L.) Todaro var. pensylvanica (Willd.) Morton | Matteuccia struthiopteris | Dryopteridaceae
|
| MASTP2 | Matteuccia struthiopteris (L.) Todaro var. pubescens (Terry) Clute | Matteuccia struthiopteris | Dryopteridaceae
|
| MAST | Matteuccia struthiopteris (L.) Todaro | ostrich fern | Dryopteridaceae
|
| MATTE | Matteuccia Todaro | ostrich fern | Dryopteridaceae
|
| MABI3 | Matthiola bicornis (Sibthorp & Sm.) DC. | Matthiola longipetala | Brassicaceae
|
| MAIN4 | Matthiola incana (L.) Ait. f. | tenweeks stock | Brassicaceae
|
| MALOB | Matthiola longipetala (Vent.) DC. ssp. bicornis (Sibthorp & Sm.) P.W. Ball | Matthiola longipetala | Brassicaceae
|
| MALO3 | Matthiola longipetala (Vent.) DC. | night scented stock | Brassicaceae
|
| MASC8 | Matthiola scabra L. | Guettarda scabra | Rubiaceae
|
| MATTH | Matthiola Ait. f. | stock | Brassicaceae
|
| MAAN9 | Maurandella antirrhiniflora (Humb. & Bonpl. ex Willd.) Rothm. | roving sailor | Scrophulariaceae
|
| MAPE7 | Maurandella petrophila (Coville & Morton) Rothm. | Holmgrenanthe petrophila | Scrophulariaceae
|
| MAURA2 | Maurandella (Gray) Rothm. | maurandella | Scrophulariaceae
|
| MAAC2 | Maurandya acerifolia Pennell | Mabrya acerifolia | Scrophulariaceae
|
| MAAN6 | Maurandya antirrhiniflora Humb. & Bonpl. ex Willd. | Maurandella antirrhiniflora | Scrophulariaceae
|
| MABA5 | Maurandya barclaiana Lindl. | Mexican viper | Scrophulariaceae
|
| MAPE | Maurandya petrophila Coville & Morton | Holmgrenanthe petrophila | Scrophulariaceae
|
| MAWI2 | Maurandya wislizeni Engelm. ex Gray | Epixiphium wislizeni | Scrophulariaceae
|
| MAURA | Maurandya Ortega | maurandya | Scrophulariaceae
|
| MAFL8 | Mauritia flexuosa L. f. | muriti | Arecaceae
|
| MAVI10 | Mauritia vinifera C. Martius | mauritia | Arecaceae
|
| MAURI | Mauritia L. f. | mauritia | Arecaceae
|
| MAAC5 | Maxillaria acutifolia Lindl. | rufous tiger orchid | Orchidaceae
|
| MACO8 | Maxillaria coccinea (Jacq.) L.O. Williams ex Hodge | flame orchid | Orchidaceae
|
| MACO9 | Maxillaria conferta (Griseb.) C. Schweinf. | Maxillaria parviflora | Orchidaceae
|
| MACR2 | Maxillaria crassifolia (Lindl.) Reichenb. f. | hidden orchid | Orchidaceae
|
| MALU5 | Maxillaria luteo-alba Lindl. | | Orchidaceae
|
| MAPA22 | Maxillaria parviflora (Poepp. & Endl.) Garay | purple tiger orchid | Orchidaceae
|
| MAPU6 | Maxillaria purpurea (Spreng.) Ames & Correll p.p. | Maxillaria parviflora | Orchidaceae
|
| MARU2 | Maxillaria rufescens auct. non Lindl. | Maxillaria acutifolia | Orchidaceae
|
| MASE3 | Maxillaria sessilis (Sw.) Fawcett & Rendle | Maxillaria crassifolia | Orchidaceae
|
| MAXIL | Maxillaria Ruiz & Pav�n | tiger orchid | Orchidaceae
|
| MAAU2 | Mayaca aubletii Michx. | Mayaca fluviatilis | Mayacaceae
|
| MAFL2 | Mayaca fluviatilis Aubl. | stream bogmoss | Mayacaceae
|
| MAYAC | Mayaca Aubl. | mayaca | Mayacaceae
|
| MAAX | Mayepea axilliflora (Griseb.) Krug & Urban | Chionanthus axilliflorus | Oleaceae
|
| MACA15 | Mayepea caribaea (Jacq.) Kuntze | Chionanthus compactus | Oleaceae
|
| MADO5 | Mayepea domingensis (Lam.) Krug & Urban | Chionanthus domingensis | Oleaceae
|
| MACY2 | Maytenus cymosa Krug & Urban | Caribbean mayten | Celastraceae
|
| MAEL2 | Maytenus elliptica (Lam.) Krug & Urban ex Duss. | Maytenus laevigata | Celastraceae
|
| MAEL3 | Maytenus elongata (Urban) Britt. | Puerto Rico mayten | Celastraceae
|
| MALA8 | Maytenus laevigata (Vahl) Griseb. ex Eggers | white cinnamon | Celastraceae
|
| MAPHO | Maytenus phyllanthoides Benth. var. ovalifolia Loes. | Maytenus phyllanthoides | Celastraceae
|
| MAPH | Maytenus phyllanthoides Benth. | Florida mayten | Celastraceae
|
| MAPO5 | Maytenus ponceana Britt. | ponce mayten | Celastraceae
|
| MATE9 | Maytenus texana Lundell | Maytenus phyllanthoides | Celastraceae
|
| MAYTE | Maytenus Molina | mayten | Celastraceae
|
| MAOC2 | Mazosia ocellata (Nyl.) R. C Harris | | Roccellaceae
|
| MAZOS | Mazosia A. Massal. | mazosia | Roccellaceae
|
| MAJA | Mazus japonicus (Thunb.) Kuntze | Mazus pumilus | Scrophulariaceae
|
| MAMI4 | Mazus miquelii Makino | Miquel's mazus | Scrophulariaceae
|
| MAPU7 | Mazus pumilus (Burm. f.) Steenis | Japanese mazus | Scrophulariaceae
|
| MARE5 | Mazus reptans N.E. Br. | Mazus miquelii | Scrophulariaceae
|
| MAZUS | Mazus Lour. | mazus | Scrophulariaceae
|
| MEACA | Mecardonia acuminata (Walt.) Small var. acuminata | axilflower | Scrophulariaceae
|
| MEACM | Mecardonia acuminata (Walt.) Small var. microphylla (Raf.) Pennell | axilflower | Scrophulariaceae
|
| MEACP | Mecardonia acuminata (Walt.) Small var. peninsularis Pennell | axilflower | Scrophulariaceae
|
| MEAC | Mecardonia acuminata (Walt.) Small | axilflower | Scrophulariaceae
|
| MEDI3 | Mecardonia dianthera Pennell | Mecardonia procumbens | Scrophulariaceae
|
| MEPE7 | Mecardonia peduncularis (Benth.) Small | Mecardonia procumbens | Scrophulariaceae
|
| MEPR2 | Mecardonia procumbens (P. Mill.) Small | baby jump-up | Scrophulariaceae
|
| METE2 | Mecardonia tenuis Small | Mecardonia procumbens | Scrophulariaceae
|
| MEVA | Mecardonia vandellioides auct. non (Kunth) Pennell | Mecardonia procumbens | Scrophulariaceae
|
| MECAR | Mecardonia Ruiz & Pav�n | mecardonia | Scrophulariaceae
|
| MEWR2 | Mecodium wrightii (Bosch) Copeland | Hymenophyllum wrightii | Hymenophyllaceae
|
| MECA | Meconella californica Torr. & Fr�m. | California fairypoppy | Papaveraceae
|
| MECO8 | Meconella collina Greene | Meconella californica | Papaveraceae
|
| MEDE4 | Meconella denticulata Greene | smallflower fairypoppy | Papaveraceae
|
| MELIP | Meconella linearis (Benth.) A. Nels. & J.F. Macbr. var. pulchella (Greene) Jepson | Platystigma linearis | Papaveraceae
|
| MELI | Meconella linearis (Benth.) A. Nels. & J.F. Macbr. | Platystigma linearis | Papaveraceae
|
| MEOC2 | Meconella octandra Greene | Meconella californica | Papaveraceae
|
| MEORD | Meconella oregana Nutt. var. denticulata (Greene) Jepson | Meconella denticulata | Papaveraceae
|
| MEOR | Meconella oregana Nutt. | white fairypoppy | Papaveraceae
|
| MECON | Meconella Nutt. | fairypoppy | Papaveraceae
|
| MEAM | Mecranium amygdalinum (Desr.) C. Wright ex Sauvalle | Mecranium latifolium | Melastomataceae
|
| MELA7 | Mecranium latifolium (Cogn.) Skean | camasey almendre | Melastomataceae
|
| MECRA | Mecranium Hook. f. | mecranium | Melastomataceae
|