| Symbol | Scientific name | Common name/Accepted name (for synonyms) | Family |
| MATE16 | Macadamia tetraphylla L. Johnson | macadamia nut | Proteaceae
|
| MACAD | Macadamia F. Muell. | macadamia | Proteaceae
|
| MAMA28 | Macaranga mappa (L.) Muell.-Arg. | pengua | Euphorbiaceae
|
| MATA3 | Macaranga tanarius (L.) Muell.-Arg. | parasol leaf tree | Euphorbiaceae
|
| MACAR | Macaranga Thouars | macaranga | Euphorbiaceae
|
| MAAL7 | Macbridea alba Chapman | white birds-in-a-nest | Lamiaceae
|
| MACA | Macbridea caroliniana (Walt.) Blake | Carolina birds-in-a-nest | Lamiaceae
|
| MAPU9 | Macbridea pulchra Ell. | Macbridea caroliniana | Lamiaceae
|
| MACBR | Macbridea Ell. ex Nutt. | macridea | Lamiaceae
|
| MABI7 | Macdougalia bigelovii (Gray) Heller | Hymenoxys bigelovii | Asteraceae
|
| MAUN3 | Macfadyena unguis-cati (L.) A.H. Gentry | catclawvine | Bignoniaceae
|
| MACFA | Macfadyena A. DC. | macfadyena | Bignoniaceae
|
| MAAM10 | Machaeranthera ammophila Reveal | Machaeranthera arida | Asteraceae
|
| MAAM4 | Machaeranthera amplifolia Woot. & Standl. | Psilactis asteroides | Asteraceae
|
| MAAN11 | Machaeranthera angustifolia Rydb., non Woot. & Standl. | Machaeranthera canescens ssp. canescens var. canescens | Asteraceae
|
| MAAN10 | Machaeranthera angustifolia Woot. & Standl. | Machaeranthera canescens ssp. canescens var. ambigua | Asteraceae
|
| MAAN8 | Machaeranthera annua (Rydb.) Shinners | Rayjacksonia annua | Asteraceae
|
| MAAQ | Machaeranthera aquifolia Greene ex Woot. & Standl. | Machaeranthera bigelovii var. bigelovii | Asteraceae
|
| MAAR5 | Machaeranthera arida B.L. Turner & Horne | arid tansyaster | Asteraceae
|
| MAAR6 | Machaeranthera arizonica Jackson & Johnston | Machaeranthera arida | Asteraceae
|
| MAASG | Machaeranthera asteroides (Torr.) Greene var. glandulosa B.L. Turner | Psilactis asteroides | Asteraceae
|
| MAASL | Machaeranthera asteroides (Torr.) Greene var. lagunensis (Keck) B.L. Turner | Psilactis asteroides | Asteraceae
|
| MAAS2 | Machaeranthera asteroides (Torr.) Greene | Psilactis asteroides | Asteraceae
|
| MAAT | Machaeranthera attenuata T.J. Howell | Machaeranthera canescens ssp. canescens var. incana | Asteraceae
|
| MAAU3 | Machaeranthera aurea (Gray) Shinners | Rayjacksonia aurea | Asteraceae
|
| MAAU4 | Machaeranthera australis (Greene) Shinners | Machaeranthera pinnatifida ssp. pinnatifida var. pinnatifida | Asteraceae
|
| MABIB | Machaeranthera bigelovii (Gray) Greene var. bigelovii | Bigelow's tansyaster | Asteraceae
|
| MABIC | Machaeranthera bigelovii (Gray) Greene var. commixta (Greene) B.L. Turner | Bigelow's tansyaster | Asteraceae
|
| MABIM | Machaeranthera bigelovii (Gray) Greene var. mucronata (Greene) B.L. Turner | Bigelow's tansyaster | Asteraceae
|
| MABI | Machaeranthera bigelovii (Gray) Greene | Bigelow's tansyaster | Asteraceae
|
| MABL2 | Machaeranthera blephariphylla (Gray) Shinners | Texas tansyaster | Asteraceae
|
| MABO2 | Machaeranthera boltoniae (Greene) B.L. Turner & Horne | Psilactis asteroides | Asteraceae
|
| MABR3 | Machaeranthera brevilingulata (Schultz-Bip. ex Hemsl.) B.L. Turner & Horne | Psilactis brevilingulata | Asteraceae
|
| MACAA | Machaeranthera canescens (Pursh) Gray ssp. canescens var. ambigua B.L. Turner | hoary tansyaster | Asteraceae
|
| MACAC3 | Machaeranthera canescens (Pursh) Gray ssp. canescens var. canescens | hoary tansyaster | Asteraceae
|
| MACAI2 | Machaeranthera canescens (Pursh) Gray ssp. canescens var. incana (Lindl.) Gray | hoary tansyaster | Asteraceae
|
| MACAL | Machaeranthera canescens (Pursh) Gray ssp. canescens var. leucanthemifolia (Greene) Welsh | whiteflower tansyaster | Asteraceae
|
| MACAS2 | Machaeranthera canescens (Pursh) Gray ssp. canescens var. sessiliflora (Nutt.) B.L. Turner | hoary tansyaster | Asteraceae
|
| MACAS3 | Machaeranthera canescens (Pursh) Gray ssp. canescens var. shastensis (Gray) B.L. Turner | Shasta tansyaster | Asteraceae
|
| MACAZ2 | Machaeranthera canescens (Pursh) Gray ssp. canescens var. ziegleri (Munz) B.L. Turner | Ziegler's tansyaster | Asteraceae
|
| MACAC | Machaeranthera canescens (Pursh) Gray ssp. canescens | hoary tansyaster | Asteraceae
|
| MACAA2 | Machaeranthera canescens (Pursh) Gray ssp. glabra (Gray) B.L. Turner var. aristata (Eastw.) B.L. Turner | hoary tansyaster | Asteraceae
|
| MACAG2 | Machaeranthera canescens (Pursh) Gray ssp. glabra (Gray) B.L. Turner var. glabra Gray | hoary tansyaster | Asteraceae
|
| MACAN | Machaeranthera canescens (Pursh) Gray ssp. glabra (Gray) B.L. Turner var. nebraskana B.L. Turner | Nebraska tansyaster | Asteraceae
|
| MACAG | Machaeranthera canescens (Pursh) Gray ssp. glabra (Gray) B.L. Turner | hoary tansyaster | Asteraceae
|
| MACAZ | Machaeranthera canescens (Pursh) Gray ssp. ziegleri Munz | Machaeranthera canescens ssp. canescens var. ziegleri | Asteraceae
|
| MACAC4 | Machaeranthera canescens (Pursh) Gray var. commixta (Greene) Welsh | Machaeranthera bigelovii var. commixta | Asteraceae
|
| MACAL3 | Machaeranthera canescens (Pursh) Gray var. latifolia (A. Nels.) Welsh, non Gray | Machaeranthera canescens ssp. canescens var. canescens | Asteraceae
|
| MACAL2 | Machaeranthera canescens (Pursh) Gray var. latifolia Gray | Psilactis asteroides | Asteraceae
|
| MACAM | Machaeranthera canescens (Pursh) Gray var. monticola Dorn | Machaeranthera canescens ssp. canescens var. canescens | Asteraceae
|
| MACAT | Machaeranthera canescens (Pursh) Gray var. tephrodes Gray | Machaeranthera canescens ssp. canescens var. incana | Asteraceae
|
| MACAV3 | Machaeranthera canescens (Pursh) Gray var. vacans (A. Nels.) Welsh | Machaeranthera canescens ssp. glabra var. aristata | Asteraceae
|
| MACAV2 | Machaeranthera canescens (Pursh) Gray var. viridis Gray | Machaeranthera canescens ssp. glabra var. glabra | Asteraceae
|
| MACAV | Machaeranthera canescens (Pursh) Gray var. viscosa (Nutt.) Piper | Machaeranthera canescens ssp. canescens var. canescens | Asteraceae
|
| MACA2 | Machaeranthera canescens (Pursh) Gray | hoary tansyaster | Asteraceae
|
| MACAC5 | Machaeranthera carnosa (Gray) Nesom var. carnosa | shrubby alkaliaster | Asteraceae
|
| MACAI3 | Machaeranthera carnosa (Gray) Nesom var. intricata (Gray) Nesom | shrubby alkaliaster | Asteraceae
|
| MACA17 | Machaeranthera carnosa (Gray) Nesom | shrubby alkaliaster | Asteraceae
|
| MACE | Machaeranthera centaureoides Greene ex Woot. & Standl. | Machaeranthera bigelovii var. bigelovii | Asteraceae
|
| MACI3 | Machaeranthera cichoriacea Greene | Machaeranthera canescens ssp. glabra var. aristata | Asteraceae
|
| MACO17 | Machaeranthera cognata (Hall) Cronq. & Keck | Xylorhiza cognata | Asteraceae
|
| MACOB | Machaeranthera coloradoensis (Gray) Osterhout var. brandegeei (Rydb.) T.J. Wats. ex R.L. Hartman | Brandegee's tansyaster | Asteraceae
|
| MACOC | Machaeranthera coloradoensis (Gray) Osterhout var. coloradoensis | Colorado tansyaster | Asteraceae
|
| MACO13 | Machaeranthera coloradoensis (Gray) Osterhout | Colorado tansyaster | Asteraceae
|
| MACO2 | Machaeranthera commixta Greene | Machaeranthera bigelovii var. commixta | Asteraceae
|
| MACO30 | Machaeranthera confertifolia (Cronq.) Cronq. | Xylorhiza confertifolia | Asteraceae
|
| MACO15 | Machaeranthera coronopifolia (Nutt.) A. Nels. | Machaeranthera tanacetifolia | Asteraceae
|
| MACO16 | Machaeranthera correllii Shinners | Machaeranthera blephariphylla | Asteraceae
|
| MACOA | Machaeranthera coulteri (Gray) B.L. Turner & Horne var. arida (B.L. Turner & Horne) B.L. Turner | Machaeranthera arida | Asteraceae
|
| MACR7 | Machaeranthera cronquistii (Welsh & Atwood) Cronq. | Xylorhiza cronquistii | Asteraceae
|
| MADI7 | Machaeranthera divaricata (Nutt.) Greene | Machaeranthera canescens ssp. canescens var. canescens | Asteraceae
|
| MAER | Machaeranthera eradiata (Gray) T.J. Howell | Machaeranthera canescens ssp. canescens var. shastensis | Asteraceae
|
| MAFR4 | Machaeranthera fremontii Rydb. | Machaeranthera canescens ssp. glabra var. glabra | Asteraceae
|
| MAGL10 | Machaeranthera glabella Greene ex Rydb. | Machaeranthera canescens ssp. canescens var. canescens | Asteraceae
|
| MAGLC | Machaeranthera glabriuscula (Nutt.) Cronq. & Keck var. confertifolia Cronq. | Xylorhiza confertifolia | Asteraceae
|
| MAGLV2 | Machaeranthera glabriuscula (Nutt.) Cronq. & Keck var. villosa (Nutt.) Cronq. & Keck | Xylorhiza glabriuscula var. villosa | Asteraceae
|
| MAGL7 | Machaeranthera glabriuscula (Nutt.) Cronq. & Keck | Xylorhiza glabriuscula var. glabriuscula | Asteraceae
|
| MAGR10 | Machaeranthera gracilis (Nutt.) Shinners | slender goldenweed | Asteraceae
|
| MAGRD | Machaeranthera grindelioides (Nutt.) Shinners var. depressa (Maguire) Cronq. & Keck | rayless tansyaster | Asteraceae
|
| MAGRG | Machaeranthera grindelioides (Nutt.) Shinners var. grindelioides | rayless tansyaster | Asteraceae
|
| MAGR2 | Machaeranthera grindelioides (Nutt.) Shinners | rayless tansyaster | Asteraceae
|
| MAGY | Machaeranthera gymnocephala auct. non (DC.) Shinners | Machaeranthera blephariphylla | Asteraceae
|
| MAGY2 | Machaeranthera gypsitherma Nesom, Vorobik & Hartman | La Playa Springs tansyaster | Asteraceae
|
| MAGY3 | Machaeranthera gypsophila B.L. Turner | gypsum tansyaster | Asteraceae
|
| MAHA6 | Machaeranthera hansonii A. Nels. | Psilactis asteroides | Asteraceae
|
| MAHA3 | Machaeranthera havardii (Waterfall) Shinners | Machaeranthera viscida | Asteraceae
|
| MAHE3 | Machaeranthera heterocarpa R.L. Hartman & M.A. Lane | Psilactis heterocarpa | Asteraceae
|
| MAHI4 | Machaeranthera hiemalis A. Nels. | Machaeranthera canescens ssp. canescens var. leucanthemifolia | Asteraceae
|
| MAIN9 | Machaeranthera incana (Lindl.) Greene | Machaeranthera canescens ssp. canescens var. incana | Asteraceae
|
| MAINA2 | Machaeranthera inops A. Nels. & J.F. Macbr. var. atrata A. Nels. & J.F. Macbr. | Machaeranthera canescens ssp. canescens var. shastensis | Asteraceae
|
| MAIN11 | Machaeranthera inops A. Nels. & J.F. Macbr. | Machaeranthera canescens ssp. canescens var. shastensis | Asteraceae
|
| MAIN10 | Machaeranthera inornata (Greene) Greene | Machaeranthera canescens ssp. canescens var. shastensis | Asteraceae
|
| MAJU | Machaeranthera juncea (Greene) Shinners | rush bristleweed | Asteraceae
|
| MAKIB | Machaeranthera kingii (D.C. Eat.) Cronq. & Keck var. barnebyana Welsh & Goodrich | Tonestus kingii var. barnebyana | Asteraceae
|
| MAKI | Machaeranthera kingii (D.C. Eat.) Cronq. & Keck | Tonestus kingii var. kingii | Asteraceae
|
| MALA3 | Machaeranthera laetevirens Greene, non Aster laetevirens (Greene) Greene | Machaeranthera canescens ssp. canescens var. canescens | Asteraceae
|
| MALA12 | Machaeranthera laevis (Woot. & Standl.) Shinners | Machaeranthera pinnatifida ssp. pinnatifida var. pinnatifida | Asteraceae
|
| MALA | Machaeranthera lagunensis Keck | Psilactis asteroides | Asteraceae
|
| MALA11 | Machaeranthera latifolia A. Nels. | Machaeranthera canescens ssp. canescens var. canescens | Asteraceae
|
| MALE6 | Machaeranthera leptophylla Rydb. | Machaeranthera canescens ssp. canescens var. canescens | Asteraceae
|
| MALE | Machaeranthera leucanthemifolia (Greene) Greene | Machaeranthera canescens ssp. canescens var. leucanthemifolia | Asteraceae
|