| Symbol | Scientific name | Common name/Accepted name (for synonyms) | Family |
| GRAF2 | Graphis afzelii Ach. | Afzel's script lichen | Graphidaceae
|
| GRAN5 | Graphis anfractuosa Eschw. | script lichen | Graphidaceae
|
| GRAP2 | Graphis aperiens Mull. Arg. | script lichen | Graphidaceae
|
| GRAT | Graphis atrorubens Tuck. ex Fink | Opegrapha longissima | Opegraphaceae
|
| GRBE | Graphis beaumontii Tuck. | Graphis insidiosa | Graphidaceae
|
| GRBO | Graphis botryosa Tuck. | script lichen | Graphidaceae
|
| GRCA6 | Graphis caesiella Vainio | script lichen | Graphidaceae
|
| GRCA7 | Graphis candidata Nyl. | script lichen | Graphidaceae
|
| GRCE2 | Graphis celtidis Mull. Arg. | Graphis librata | Graphidaceae
|
| GRCH | Graphis chromothecia R. C. Harris | script lichen | Graphidaceae
|
| GRDE3 | Graphis desquamescens (Fee) Zahlbr. | script lichen | Graphidaceae
|
| GRDU2 | Graphis dumastioides Fink | script lichen | Graphidaceae
|
| GREL | Graphis elegans (Borrer ex Sm.) Ach. | elegant script lichen | Graphidaceae
|
| GREU | Graphis eulectra Tuck. | script lichen | Graphidaceae
|
| GRFL4 | Graphis floridana Tuck. | Graphina floridana | Graphidaceae
|
| GRGL | Graphis glaucescens Fee | script lichen | Graphidaceae
|
| GRGR5 | Graphis grammatis Fee | script lichen | Graphidaceae
|
| GRHA7 | Graphis haleana R. C. Harris | script lichen | Graphidaceae
|
| GRIL | Graphis illiterata R. C. Harris | script lichen | Graphidaceae
|
| GRIN6 | Graphis insidiosa (C. Knight & Mitten) Hook. f. | script lichen | Graphidaceae
|
| GRIN7 | Graphis intertexta Mull. Arg. | Graphina intertexta | Graphidaceae
|
| GRIN8 | Graphis intricata Fee | script lichen | Graphidaceae
|
| GRIN12 | Graphis inversa R. C. Harris | script lichen | Graphidaceae
|
| GRLE7 | Graphis leptocarpa Fee | script lichen | Graphidaceae
|
| GRLE4 | Graphis leucopepla Tuck. | script lichen | Graphidaceae
|
| GRLI6 | Graphis librata C. Knight | script lichen | Graphidaceae
|
| GRLI5 | Graphis lineola Ach. | script lichen | Graphidaceae
|
| GRLU2 | Graphis lucifica R. C. Harris | script lichen | Graphidaceae
|
| GRLU3 | Graphis lumbricina Vainio | script lichen | Graphidaceae
|
| GRMO3 | Graphis mosquitensis Tuck. | mosquito script lichen | Graphidaceae
|
| GRNI3 | Graphis nitida (Eschw.) Tuck. | Medusulina nitida | Graphidaceae
|
| GRPA4 | Graphis pavoniana Fee | script lichen | Graphidaceae
|
| GRPL3 | Graphis platycarpella Mull. Arg. | script lichen | Graphidaceae
|
| GRPO | Graphis poitaeoides Nyl. | script lichen | Graphidaceae
|
| GRRI | Graphis rimulosa (Mont.) Trevisan | script lichen | Graphidaceae
|
| GRRU2 | Graphis rufula (Trevisan) Mont. | script lichen | Graphidaceae
|
| GRSA3 | Graphis saxorum Egea & Torrente | script lichen | Graphidaceae
|
| GRSC3 | Graphis scripta (L.) Ach. | pencilmark lichen | Graphidaceae
|
| GRST4 | Graphis striatula (Ach.) Sprengel | script lichen | Graphidaceae
|
| GRSU7 | Graphis subamylacea Zahlbr. | script lichen | Graphidaceae
|
| GRSU13 | Graphis subelegans Nyl. | script lichen | Graphidaceae
|
| GRSU8 | Graphis subnitidula Nyl. | script lichen | Graphidaceae
|
| GRSU9 | Graphis subparilis Nyl. | script lichen | Graphidaceae
|
| GRTE3 | Graphis tenella Ach. | script lichen | Graphidaceae
|
| GRTU2 | Graphis turbulenta Nyl. | script lichen | Graphidaceae
|
| GRAPH2 | Graphis Adans. | script lichen | Graphidaceae
|
| GRBA3 | Graptopetalum bartramii Rose | Patagonia Mountain leatherpetal | Crassulaceae
|
| GROR | Graptopetalum orpetii E. Walther | Graptopetalum rusbyi | Crassulaceae
|
| GRRU | Graptopetalum rusbyi (Greene) Rose | San Francisco River leatherpetal | Crassulaceae
|
| GRAPT | Graptopetalum Rose | leatherpetal | Crassulaceae
|
| GRPI4 | Graptophyllum pictum (L.) Griffith | | Acanthaceae
|
| GRAPT4 | Graptophyllum Nees | graptophyllum | Acanthaceae
|
| GRAUO | Gratiola aurea Pursh var. obtusa Pennell | Gratiola aurea | Scrophulariaceae
|
| GRAU | Gratiola aurea Pursh | golden hedgehyssop | Scrophulariaceae
|
| GRBR | Gratiola brevifolia Raf. | sticky hedgehyssop | Scrophulariaceae
|
| GRDU | Gratiola dubia L. | Lindernia dubia var. dubia | Scrophulariaceae
|
| GREB | Gratiola ebracteata Benth. ex A. DC. | bractless hedgehyssop | Scrophulariaceae
|
| GRFL | Gratiola flava Leavenworth | yellow hedgehyssop | Scrophulariaceae
|
| GRFL2 | Gratiola floridana Nutt. | Florida hedgehyssop | Scrophulariaceae
|
| GRHE | Gratiola heterosepala Mason & Bacig. | Boggs Lake hedgehyssop | Scrophulariaceae
|
| GRHI2 | Gratiola hispida (Benth. ex Lindl.) Pollard | rough hedgehyssop | Scrophulariaceae
|
| GRLU | Gratiola lutea Raf. | Gratiola aurea | Scrophulariaceae
|
| GRNEG | Gratiola neglecta Torr. var. glaberrima Fern. | Gratiola neglecta | Scrophulariaceae
|
| GRNE | Gratiola neglecta Torr. | clammy hedgehyssop | Scrophulariaceae
|
| GROF | Gratiola officinalis L. | hedgehyssop | Scrophulariaceae
|
| GRPIE | Gratiola pilosa Michx. var. epilis Pennell | Gratiola pilosa | Scrophulariaceae
|
| GRPI | Gratiola pilosa Michx. | shaggy hedgehyssop | Scrophulariaceae
|
| GRRA | Gratiola ramosa Walt. | branched hedgehyssop | Scrophulariaceae
|
| GRRE3 | Gratiola repens Sw. | Bacopa repens | Scrophulariaceae
|
| GRSP3 | Gratiola sphaerocarpa Ell. | Gratiola virginiana var. virginiana | Scrophulariaceae
|
| GRSU3 | Gratiola subulata Baldw. ex Benth. | Gratiola hispida | Scrophulariaceae
|
| GRVIA | Gratiola virginiana L. var. aestuariorum Pennell | roundfruit hedgehyssop | Scrophulariaceae
|
| GRVIV | Gratiola virginiana L. var. virginiana | roundfruit hedgehyssop | Scrophulariaceae
|
| GRVI | Gratiola virginiana L. | roundfruit hedgehyssop | Scrophulariaceae
|
| GRVIS2 | Gratiola viscidula Pennell ssp. shortii Dur. ex Pennell | Gratiola viscidula | Scrophulariaceae
|
| GRVIS | Gratiola viscidula Pennell var. shortii (Dur. ex Pennell) Gleason | Gratiola viscidula | Scrophulariaceae
|
| GRVI2 | Gratiola viscidula Pennell | Short's hedgehyssop | Scrophulariaceae
|
| GRVI4 | Gratiola viscosa Schwein. | Gratiola viscidula | Scrophulariaceae
|
| GRATI | Gratiola L. | hedgehyssop | Scrophulariaceae
|
| GRBRP | Grayia brandegeei Gray var. plummeri Stutz & Sanderson | Zuckia brandegeei var. plummeri | Chenopodiaceae
|
| GRBR2 | Grayia brandegeei Gray | Zuckia brandegeei var. brandegeei | Chenopodiaceae
|
| GRSP | Grayia spinosa (Hook.) Moq. | spiny hopsage | Chenopodiaceae
|
| GRAYI | Grayia Hook. & Arn. | hopsage | Chenopodiaceae
|
| GRAR3 | Greenella arizonica Gray | Gutierrezia arizonica | Asteraceae
|
| GRDI | Greenella discoidea Gray | Gutierrezia wrightii | Asteraceae
|
| GRCIH | Greeneocharis circumscissa (Hook. & Arn.) Rydb. var. hispida J.F. Macbr. | Cryptantha circumscissa var. hispida | Boraginaceae
|
| GRCI | Greeneocharis circumscissa (Hook. & Arn.) Rydb. | Cryptantha circumscissa var. circumscissa | Boraginaceae
|
| GRCAL | Greggia camporum Gray var. linearifolia (S. Wats.) M.E. Jones | Nerisyrenia linearifolia | Brassicaceae
|
| GRCA2 | Greggia camporum Gray | Nerisyrenia camporum | Brassicaceae
|
| GRMO2 | Gregoria montana (Gray) House | Douglasia montana | Primulaceae
|
| GRBA | Grevillea banksii R. Br. | kahiliflower | Proteaceae
|
| GRRO | Grevillea robusta A. Cunningham ex R. Br. | silkoak | Proteaceae
|
| GREVI | Grevillea R. Br. ex Knight | grevillea | Proteaceae
|
| GRSE8 | Grevilleanum serratum Beck & Emmons | Timmia megapolitana var. megapolitana | Timmiaceae
|
| GRAS2 | Grewia asiatica L. | phalsa | Tiliaceae
|
| GRBI2 | Grewia biloba G. Don | bilobed grewia | Tiliaceae
|
| GRSI3 | Grewia similis K. Schum. | | Tiliaceae
|
| GREWI | Grewia L. | grewia | Tiliaceae
|
| GRRA4 | Greyia radlkoferi Szyszyl. | Natal bottlebrush | Greyiaceae
|
| GREYI | Greyia Hook. & Harv. | Natal bottlebrush | Greyiaceae
|
| GRAF70 | Grimmia affinis Hoppe & Hornsch. ex Hornsch. | grimmia dry rock moss | Grimmiaceae
|