| Symbol | Scientific name | Common name/Accepted name (for synonyms) | Family |
| RASI2 | Ranunculus siciformis Mackenzie & Bush ex Rydb. | Ranunculus hispidus var. caricetorum | Ranunculaceae
|
| RAST3 | Ranunculus stolonifer Hemsl. | Ranunculus hydrocharoides var. stolonifer | Ranunculaceae
|
| RASU3 | Ranunculus subcordatus E.O. Beal | Ranunculus laxicaulis | Ranunculaceae
|
| RASU | Ranunculus subrigidus W. Drew | Ranunculus longirostris | Ranunculaceae
|
| RASU4 | Ranunculus suksdorfii Gray | Suksdorf's buttercup | Ranunculaceae
|
| RASUI | Ranunculus sulphureus Soland. ex C.J. Phipps var. intercedens Hult�n | Ranunculus sulphureus | Ranunculaceae
|
| RASU2 | Ranunculus sulphureus Soland. ex C.J. Phipps | sulphur buttercup | Ranunculaceae
|
| RATE7 | Ranunculus tener C. Mohr | Ranunculus pusillus var. angustifolius | Ranunculaceae
|
| RATE | Ranunculus testiculatus Crantz | Ceratocephala testiculata | Ranunculaceae
|
| RATE6 | Ranunculus texensis Engelm. | Ranunculus laxicaulis | Ranunculaceae
|
| RATR5 | Ranunculus trachycarpus Fisch. & C.A. Mey. | Ranunculus marginatus var. trachycarpus | Ranunculaceae
|
| RATRE2 | Ranunculus trichophyllus Chaix ssp. eradicatus (Laestad.) C.D.K. Cook | Ranunculus trichophyllus var. eradicatus | Ranunculaceae
|
| RATRL | Ranunculus trichophyllus Chaix ssp. lutulentus (Perrier & Song.) Vierh. | Ranunculus trichophyllus var. eradicatus | Ranunculaceae
|
| RATRC2 | Ranunculus trichophyllus Chaix var. calvescens W. Drew | Ranunculus trichophyllus var. trichophyllus | Ranunculaceae
|
| RATRC | Ranunculus trichophyllus Chaix var. confervoides (Fries) Rikli | Ranunculus trichophyllus var. eradicatus | Ranunculaceae
|
| RATRE | Ranunculus trichophyllus Chaix var. eradicatus (Laestad.) W. Drew | threadleaf crowfoot | Ranunculaceae
|
| RATRH | Ranunculus trichophyllus Chaix var. hispidulus (E. Drew) W. Drew | Ranunculus aquatilis | Ranunculaceae
|
| RATRT | Ranunculus trichophyllus Chaix var. trichophyllus | threadleaf crowfoot | Ranunculaceae
|
| RATRT2 | Ranunculus trichophyllus Chaix var. typicus W. Drew | Ranunculus trichophyllus var. trichophyllus | Ranunculaceae
|
| RATR | Ranunculus trichophyllus Chaix | threadleaf crowfoot | Ranunculaceae
|
| RATR2 | Ranunculus trilobus Desf. | threelobe buttercup | Ranunculaceae
|
| RATR4 | Ranunculus trisectus Eastw. | Ranunculus eschscholtzii var. trisectus | Ranunculaceae
|
| RATR3 | Ranunculus trisepalus Gillies ex Hook. & Arn. | Ranunculus bonariensis var. trisepalus | Ranunculaceae
|
| RATR6 | Ranunculus triternatus Gray | obscure buttercup | Ranunculaceae
|
| RATU | Ranunculus turneri Greene | Turner's buttercup | Ranunculaceae
|
| RAUNE | Ranunculus uncinatus D. Don ex G. Don var. earlei (Greene) L. Benson | Earle's buttercup | Ranunculaceae
|
| RAUNP | Ranunculus uncinatus D. Don ex G. Don var. parviflorus (Torr.) L. Benson | Idaho buttercup | Ranunculaceae
|
| RAUNT | Ranunculus uncinatus D. Don ex G. Don var. typicus L. Benson | Ranunculus uncinatus var. uncinatus | Ranunculaceae
|
| RAUNU | Ranunculus uncinatus D. Don ex G. Don var. uncinatus | woodland buttercup | Ranunculaceae
|
| RAUN | Ranunculus uncinatus D. Don ex G. Don | woodland buttercup | Ranunculaceae
|
| RAUS | Ranunculus usneoides Greene | Ranunculus longirostris | Ranunculaceae
|
| RAVE | Ranunculus verecundus B.L. Robins. ex Piper | wetslope buttercup | Ranunculaceae
|
| RANUN | Ranunculus L. | buttercup | Ranunculaceae
|
| RACO5 | Rapanea coriacea (Sw.) Mez | Myrsine coriacea | Myrsinaceae
|
| RAFE2 | Rapanea ferruginea (Ruiz & Pav�n) Mez | Myrsine coriacea | Myrsinaceae
|
| RAGU2 | Rapanea guianensis auct. non Aubl. | Myrsine floridana | Myrsinaceae
|
| RAPU2 | Rapanea punctata (Lam.) Lundell | Myrsine floridana | Myrsinaceae
|
| RAER | Raphanus eruca (L.) Crantz | Eruca vesicaria ssp. sativa | Brassicaceae
|
| RALA5 | Raphanus lanceolatus Willd. | Cakile lanceolata ssp. lanceolata | Brassicaceae
|
| RARAS | Raphanus raphanistrum L. var. sativus (L.) G. Beck | Raphanus sativus | Brassicaceae
|
| RARA2 | Raphanus raphanistrum L. | wild radish | Brassicaceae
|
| RASA2 | Raphanus sativus L. | cultivated radish | Brassicaceae
|
| RAPHA | Raphanus L. | radish | Brassicaceae
|
| RAFA5 | Raphia farinifera (Gaertner) Hylander | raffia palm | Arecaceae
|
| RAHO3 | Raphia hookeri G. Mann & H. A. Wendl. | Ivory Coast raphia palm | Arecaceae
|
| RAPE8 | Raphia pedunculata P. Beauv. | Raphia farinifera | Arecaceae
|
| RASU8 | Raphia sudanica A. Chev. | Sudan raphia palm | Arecaceae
|
| RAVI2 | Raphia vinifera P. Beauv. | West African piassava palm | Arecaceae
|
| RAPHI | Raphia P. Beauv. | raffia palm | Arecaceae
|
| RAPE4 | Rapistrum perenne (L.) All. | perennial bastardcabbage | Brassicaceae
|
| RARUO | Rapistrum rugosum (L.) All. ssp. orientale (L.) Arcang. | oriental bastardcabbage | Brassicaceae
|
| RARUR2 | Rapistrum rugosum (L.) All. ssp. rugosum | annual bastardcabbage | Brassicaceae
|
| RARU | Rapistrum rugosum (L.) All. | annual bastardcabbage | Brassicaceae
|
| RAPIS | Rapistrum Crantz | bastardcabbage | Brassicaceae
|
| RACOP | Ratibida columnaris D. Don var. pulcherrima (DC.) D. Don | Ratibida columnifera | Asteraceae
|
| RACO7 | Ratibida columnaris D. Don | Ratibida columnifera | Asteraceae
|
| RACO3 | Ratibida columnifera (Nutt.) Woot. & Standl. | upright prairie coneflower | Asteraceae
|
| RAPEP2 | Ratibida peduncularis (Torr. & Gray) Barnh. var. peduncularis | naked Mexicanhat | Asteraceae
|
| RAPEP | Ratibida peduncularis (Torr. & Gray) Barnh. var. picta (Gray) Sharp | naked Mexicanhat | Asteraceae
|
| RAPE3 | Ratibida peduncularis (Torr. & Gray) Barnh. | naked Mexicanhat | Asteraceae
|
| RAPI2 | Ratibida picta (Gray) Small | Ratibida peduncularis var. picta | Asteraceae
|
| RAPI | Ratibida pinnata (Vent.) Barnh. | pinnate prairie coneflower | Asteraceae
|
| RATA | Ratibida tagetes (James) Barnh. | green prairie coneflower | Asteraceae
|
| RATIB | Ratibida Raf. | prairie coneflower | Asteraceae
|
| RADO2 | Ratonia domingensis DC. | Matayba domingensis | Sapindaceae
|
| RAPR3 | Rauia praelonga (Schimp. ex Besch.) Broth. ex Par. | Rauiella praelonga | Thuidiaceae
|
| RASC7 | Rauia scita (P. Beauv.) Aust. | Rauiella scita | Thuidiaceae
|
| RAPR2 | Rauiella praelonga (Schimp. ex Besch.) Wijk & Marg. | rauiella moss | Thuidiaceae
|
| RASC6 | Rauiella scita (P. Beauv.) Reim. | rauiella moss | Thuidiaceae
|
| RAUIE | Rauiella Reim. | rauiella moss | Thuidiaceae
|
| RACA8 | Rauvolfia canescens L. | Rauvolfia tetraphylla | Apocynaceae
|
| RADE | Rauvolfia degeneri Sherff | Rauvolfia sandwicensis | Apocynaceae
|
| RAFO | Rauvolfia forbesii Sherff | Rauvolfia sandwicensis | Apocynaceae
|
| RAHE4 | Rauvolfia helleri Sherff | Rauvolfia sandwicensis | Apocynaceae
|
| RAHE7 | Rauvolfia heterophylla Roemer & Schultes | Rauvolfia tetraphylla | Apocynaceae
|
| RALA3 | Rauvolfia lamarckii A. DC. | Rauvolfia viridis | Apocynaceae
|
| RAMA6 | Rauvolfia mauiensis Sherff | Rauvolfia sandwicensis | Apocynaceae
|
| RAMOP | Rauvolfia molokaiensis Sherff var. parvifolia O. Deg. & Sherff | Rauvolfia sandwicensis | Apocynaceae
|
| RAMO | Rauvolfia molokaiensis Sherff | Rauvolfia sandwicensis | Apocynaceae
|
| RANI2 | Rauvolfia nitida Jacq. | palo amargo | Apocynaceae
|
| RARE4 | Rauvolfia remotiflora O. Deg. & Sherff | Rauvolfia sandwicensis | Apocynaceae
|
| RASAS | Rauvolfia sandwicensis A. DC. var. subcuminata Sherff | Rauvolfia sandwicensis | Apocynaceae
|
| RASA3 | Rauvolfia sandwicensis A. DC. | devil's-pepper | Apocynaceae
|
| RASE4 | Rauvolfia serpentina (L.) Benth. ex Kurz | serpentine wood | Apocynaceae
|
| RATE8 | Rauvolfia tetraphylla L. | be still tree | Apocynaceae
|
| RATE3 | Rauvolfia tetraphylla auct. non L. | Rauvolfia nitida | Apocynaceae
|
| RATE3 | Rauvolfia tetraphylla auct. non L. | Rauvolfia sandwicensis | Apocynaceae
|
| RAVI | Rauvolfia viridis Willd. ex Roemer & J.A. Schultes | milkbush | Apocynaceae
|
| RAVO | Rauvolfia vomitoria Afzelius | poison devil's-pepper | Apocynaceae
|
| RAUVO | Rauvolfia L. | devil's-pepper | Apocynaceae
|
| RAMA7 | Ravenala madagascariensis Sonnerat | traveler's tree | Musaceae
|
| RAVEN2 | Ravenala Adans. | traveler's tree | Musaceae
|
| RAUR | Ravenia urbanii Engl. ex Urban | tortugo prieto | Rutaceae
|
| RAVEN | Ravenia Vell. | ravenia | Rutaceae
|
| RAAN2 | Rayjacksonia annua (Rydb.) R.L. Hartman & M.A. Lane | viscid tansyaster | Asteraceae
|
| RAAU4 | Rayjacksonia aurea (Gray) R.L. Hartman & M.A. Lane | Houston tansyaster | Asteraceae
|
| RAPH2 | Rayjacksonia phyllocephala (DC.) R.L. Hartman & M.L. Lane | camphor daisy | Asteraceae
|
| RAYJA | Rayjacksonia R.L. Hartman & M.A. Lane | tansyaster | Asteraceae
|
| RAPU4 | Razoumofskya pusilla (Peck) Kuntze | Arceuthobium pusillum | Viscaceae
|
| REHEA | Reboulia hemisphaerica (L.) Raddi ssp. acrogyna (R. M. Schust.) R. M. Schust. | | Aytoniaceae
|
| REHEA2 | Reboulia hemisphaerica (L.) Raddi ssp. australis R. M. Schust. | | Aytoniaceae
|