| Symbol | Scientific name | Common name/Accepted name (for synonyms) | Family |
| MIKU | Microchloa kunthii Desv. | Kunth's smallgrass | Poaceae
|
| MICRO | Microchloa R. Br. | smallgrass | Poaceae
|
| MIAU4 | Microcitrus australasica (F. Muell.) Swingle | Australian finger lime | Rutaceae
|
| MIAU5 | Microcitrus australis (Planchon) Swingle | Australian round lime | Rutaceae
|
| MICRO17 | Microcitrus Swingle | microcitrus | Rutaceae
|
| MICO17 | Microglaena corrosa (Korber) Arnold | Protothelenella corrosa | Protothelenellaceae
|
| MIHA2 | Microglaena hassei Zahlbr. | Thelenella hassei | Thelenellaceae
|
| MIIN11 | Microglaena inductula (Nyl.) Servit | Thelenella inductula | Thelenellaceae
|
| MIMU5 | Microglaena muscorum (Fr.) Th. Fr. | Chromatochlamys muscorum | Thelenellaceae
|
| MISO | Microglaena sordidula Th. Fr. | Thelenella modesta | Thelenellaceae
|
| MISP4 | Microglaena sphinctrinoides (Nyl.) Lonnr. | Protothelenella sphinctrinoides | Protothelenellaceae
|
| MISU9 | Microglaena subcorallina Hasse | Thelenella modesta | Thelenellaceae
|
| MISY3 | Microglaena sychnogonoides Zahlbr. | Thelenella hassei | Thelenellaceae
|
| MIHE2 | Microgramma heterophylla (L.) Wherry | clinging snakefern | Polypodiaceae
|
| MILY | Microgramma lycopodioides (L.) Copeland | clubmoss snakefern | Polypodiaceae
|
| MIPI4 | Microgramma piloselloides (L.) Copeland | hairy snakefern | Polypodiaceae
|
| MICRO9 | Microgramma K. Presl | snakefern | Polypodiaceae
|
| MIST | Microlaena stipoides (Labill.) R. Br. | Ehrharta stipoides | Poaceae
|
| MIHI4 | Microlepia hirta (Kaulfuss) K. Presl | Microlepia strigosa | Dennstaedtiaceae
|
| MIMA11 | Microlepia mauiensis W.H. Wagner | Maui fern | Dennstaedtiaceae
|
| MISE | Microlepia setosa (Sm.) Alston | Microlepia strigosa | Dennstaedtiaceae
|
| MISP2 | Microlepia speluncae (L.) T. Moore | limpleaf fern | Dennstaedtiaceae
|
| MISTH | Microlepia strigosa (Thunb.) K. Presl var. hirta (Kaulfuss) Hbd. | Microlepia strigosa | Dennstaedtiaceae
|
| MIST4 | Microlepia strigosa (Thunb.) K. Presl | palapalai | Dennstaedtiaceae
|
| MICRO3 | Microlepia K. Presl | palapalai | Dennstaedtiaceae
|
| MIEP | Microlychnus epicorticis A. Funk | | Asterothyriaceae
|
| MICRO16 | Microlychnus A. Funk | microlychnus | Asterothyriaceae
|
| MIBRP | Micromeria brownei (Sw.) Benth. var. pilosiuscula Gray | Clinopodium brownei | Lamiaceae
|
| MIBR9 | Micromeria brownei (Sw.) Benth. | Clinopodium brownei | Lamiaceae
|
| MICH2 | Micromeria chamissonis (Benth.) Greene | Clinopodium douglasii | Lamiaceae
|
| MIPI7 | Micromeria pilosiuscula (Gray) Small | Clinopodium brownei | Lamiaceae
|
| MIAUF | Micromitrium austinii Sull. in Aust. var. floridanum (Grout) Crosby | Micromitrium austinii | Ephemeraceae
|
| MIAU6 | Micromitrium austinii Sull. in Aust. | Austin's micromitrium moss | Ephemeraceae
|
| MIME7 | Micromitrium megalosporum Aust. | micromitrium moss | Ephemeraceae
|
| MISY4 | Micromitrium synoicum (James) Aust. in Sull. | micromitrium moss | Ephemeraceae
|
| MITE10 | Micromitrium tenerum (Bruch & Schimp. in B.S.G.) Crosby | micromitrium moss | Ephemeraceae
|
| MIWR2 | Micromitrium wrightii (C. M�ll.) Crosby | Wright's micromitrium moss | Ephemeraceae
|
| MICRO14 | Micromitrium Aust. | micromitrium moss | Ephemeraceae
|
| MICH | Micropholis chrysophylloides Pierre | Micropholis guyanensis | Sapotaceae
|
| MICU4 | Micropholis curvata (Pierre) Pierre & Urban | Micropholis guyanensis | Sapotaceae
|
| MIGA | Micropholis garciniifolia Pierre | caimitillo verde | Sapotaceae
|
| MIGU2 | Micropholis guyanensis (A. DC.) Pierre | wild balata | Sapotaceae
|
| MICRO4 | Micropholis (Griseb.) Pierre | micropholis | Sapotaceae
|
| MIHU | Micropiper humile (Vahl) Small | Peperomia humilis | Piperaceae
|
| MILE8 | Micropiper leptostachyon (Nutt.) Small | Peperomia humilis | Piperaceae
|
| MICR | Micropteryx crista-galli (L.) Walp. | Erythrina crista-galli | Fabaceae
|
| MIAM2 | Micropus amphibola Gray | Mount Diablo cottonseed | Asteraceae
|
| MICAC2 | Micropus californicus Fisch. & C.A. Mey. var. californicus | q tips | Asteraceae
|
| MICAS | Micropus californicus Fisch. & C.A. Mey. var. subvestitus Gray | q tips | Asteraceae
|
| MICA | Micropus californicus Fisch. & C.A. Mey. | q tips | Asteraceae
|
| MICRO5 | Micropus L. | cottonseed | Asteraceae
|
| MIPU10 | Micropyxis pumila (Sw.) Duby | Anagallis pumila | Primulaceae
|
| MIER | Microrhamnus ericoides Gray | Condalia ericoides | Rhamnaceae
|
| MIPE10 | Microschizaea pennula (Sw.) C.F. Reed | Actinostachys pennula | Schizaeaceae
|
| MIAC | Microseris acuminata Greene | Sierra foothill silverpuffs | Asteraceae
|
| MIAL7 | Microseris alpestris (Gray) Q. Jones ex Cronq. | Nothocalais alpestris | Asteraceae
|
| MIBI | Microseris bigelovii (Gray) Schultz-Bip. | coastal silverpuffs | Asteraceae
|
| MIBO | Microseris borealis (Bong.) Schultz-Bip. | apargidium | Asteraceae
|
| MICA2 | Microseris campestris Greene | San Joaquin silverpuffs | Asteraceae
|
| MICU6 | Microseris cuspidata (Pursh) Schultz-Bip. | Nothocalais cuspidata | Asteraceae
|
| MIDE | Microseris decipiens Chambers | Stebbinsoseris decipiens | Asteraceae
|
| MIDOD | Microseris douglasii (DC.) Schultz-Bip. ssp. douglasii | Douglas' silverpuffs | Asteraceae
|
| MIDOP | Microseris douglasii (DC.) Schultz-Bip. ssp. platycarpha (Gray) Chambers | Douglas' silverpuffs | Asteraceae
|
| MIDOT | Microseris douglasii (DC.) Schultz-Bip. ssp. tenella (Gray) Chambers | Douglas' silverpuffs | Asteraceae
|
| MIDOP2 | Microseris douglasii (DC.) Schultz-Bip. var. platycarpha (Gray) B.L. Turner | Microseris douglasii ssp. platycarpha | Asteraceae
|
| MIDO | Microseris douglasii (DC.) Schultz-Bip. | Douglas' silverpuffs | Asteraceae
|
| MIEL | Microseris elegans Greene ex Gray | elegant silverpuffs | Asteraceae
|
| MIHE | Microseris heterocarpa (Nutt.) Chambers | Stebbinsoseris heterocarpa | Asteraceae
|
| MIHO2 | Microseris howellii Gray | Howell's silverpuffs | Asteraceae
|
| MILAD | Microseris laciniata (Hook.) Schultz-Bip. ssp. detlingii Chambers | Detling's silverpuffs | Asteraceae
|
| MILAL | Microseris laciniata (Hook.) Schultz-Bip. ssp. laciniata | cutleaf silverpuffs | Asteraceae
|
| MILAL2 | Microseris laciniata (Hook.) Schultz-Bip. ssp. leptosepala (Nutt.) Chambers | cutleaf silverpuffs | Asteraceae
|
| MILAS | Microseris laciniata (Hook.) Schultz-Bip. var. siskiyouensis Chambers | cutleaf silverpuffs | Asteraceae
|
| MILA | Microseris laciniata (Hook.) Schultz-Bip. | cutleaf silverpuffs | Asteraceae
|
| MILI5 | Microseris lindleyi (DC.) Gray | Uropappus lindleyi | Asteraceae
|
| MILI | Microseris linearifolia (Nutt.) Schultz-Bip. | Uropappus lindleyi | Asteraceae
|
| MINI3 | Microseris nigrescens Henderson | Nothocalais nigrescens | Asteraceae
|
| MINUS | Microseris nutans (Hook.) Schultz-Bip. ssp. siskiyouensis Chambers | Microseris laciniata var. siskiyouensis | Asteraceae
|
| MINU | Microseris nutans (Hook.) Schultz-Bip. | nodding microceris | Asteraceae
|
| MIPA | Microseris paludosa (Greene) J.T. Howell | marsh silverpuffs | Asteraceae
|
| MISY | Microseris sylvatica (Benth.) Schultz-Bip. | sylvan scorzonella | Asteraceae
|
| MITR5 | Microseris troximoides Gray | Nothocalais troximoides | Asteraceae
|
| MICRO6 | Microseris D. Don | silverpuffs | Asteraceae
|
| MISC2 | Microsorum scolopendria (Burm. f.) Copeland | monarch fern | Polypodiaceae
|
| MISP3 | Microsorum spectrum (Kaulfuss) Copeland | triploid fern | Polypodiaceae
|
| MICRO12 | Microsorum Link | microsorum | Polypodiaceae
|
| MIVII | Microstegium vimineum (Trin.) A. Camus var. imberbe (Nees) Honda | Microstegium vimineum | Poaceae
|
| MIVI | Microstegium vimineum (Trin.) A. Camus | Nepalese browntop | Poaceae
|
| MICRO7 | Microstegium Nees | browntop | Poaceae
|
| MIGRH2 | Microsteris gracilis (Hook.) Greene ssp. humilis (Greene) Brand | Phlox gracilis ssp. humilis | Polemoniaceae
|
| MIGRH | Microsteris gracilis (Hook.) Greene var. humilior (Hook.) Cronq. | Phlox gracilis ssp. humilis | Polemoniaceae
|
| MIGR | Microsteris gracilis (Hook.) Greene | Phlox gracilis ssp. gracilis | Polemoniaceae
|
| MIHU2 | Microsteris humilis Greene | Phlox gracilis ssp. humilis | Polemoniaceae
|
| MIMI17 | Microsteris micrantha (Kellogg) Greene | Phlox gracilis ssp. humilis | Polemoniaceae
|
| MIPO8 | Microstylis porphyrea Ridley | Malaxis porphyrea | Orchidaceae
|
| MIUN4 | Microstylis unifolia (Michx.) B.S.P. | Malaxis unifolia | Orchidaceae
|
| MIDE7 | Microtea debilis Sw. | weak jumby pepper | Chenopodiaceae
|
| MIPO | Microtea portoricensis Urban | Puerto Rico jumby pepper | Chenopodiaceae
|
| MICRO10 | Microtea Sw. | jumby pepper | Chenopodiaceae
|
| MIAT2 | Microthelia aterrima (Krempelh. ex Anzi) Zahlbr. | Lichenothelia scopularia | Lichenotheliaceae
|
| MIIN12 | Microthelia inops Degel. | Kirschsteiniothelia aethiops | Pleosporaceae
|