R
- Ranunculus abortivus (N)
- Ranunculus acris var. acris (N)
- Ranunculus acris var. acris (I)
- Ranunculus allegheniensis (N)
- Ranunculus ambigens (N)
- Ranunculus arvensis (I)
- Ranunculus bulbosus (I)
- Ranunculus fascicularis (N)
- Ranunculus ficaria var. bulbifera (I)
- Ranunculus flabellaris (N)
- Ranunculus hispidus var. caricetorum (N)
- Ranunculus hispidus var. hispidus (N)
- Ranunculus hispidus var. nitidus (N)
- Ranunculus longirostris (N)
- Ranunculus micranthus (N)
- Ranunculus parviflorus (I)
- Ranunculus pensylvanicus (N)
- Ranunculus pusillus var. pusillus (N)
- Ranunculus recurvatus var. recurvatus (N)
- Ranunculus repens (I)
- Ranunculus sceleratus var. sceleratus (N)
- Raphanus raphanistrum (I)
- Raphanus sativus (I)
- Ratibida columnifera (N)
- Ratibida pinnata (N)
- Reseda alba (I)
- Reseda lutea (I)
- Reseda luteola (I)
- Rhamnus alnifolia (N)
- Rhamnus cathartica (I)
- Rhamnus davurica ssp. davurica (I)
- Rhamnus lanceolata ssp. glabrata (N)
- Rhamnus lanceolata ssp. lanceolata (N)
- Rhamnus utilis (I)
- Rheum rhabarbarum (I)
- Rhexia virginica (N)
- Rhododendron calendulaceum (N)
- Rhododendron maximum (N)
- Rhododendron periclymenoides (N)
- Rhododendron prinophyllum (N)
- Rhodotypos scandens (I)
- Rhus aromatica var. arenaria (N)
- Rhus aromatica var. aromatica (N)
- Rhus copallinum var. latifolia (N)
- Rhus glabra (N)
- Rhus pulvinata (N)
- Rhus typhina (N)
- Rhynchospora alba (N)
- Rhynchospora capillacea (N)
- Rhynchospora capitellata (N)
- Rhynchospora recognita (N)
- Ribes americanum (N)
- Ribes aureum var. villosum (N)
- Ribes cynosbati (N)
- Ribes glandulosum (N)
- Ribes hirtellum (N)
- Ribes missouriense (N)
- Ribes nigrum (I)
- Ribes oxyacanthoides ssp. oxyacanthoides (N)
- Ribes rotundifolium (N)
- Ribes rubrum (I)
- Ribes triste (N)
- Ribes uva-crispa var. sativum (I)
- Ricinus communis (I)
- Robinia × ambigua (N)
- Robinia hispida var. fertilis (N)
- Robinia hispida var. hispida (N)
- Robinia pseudoacacia (N)
- Robinia viscosa var. viscosa (N)
- Rorippa palustris ssp. fernaldiana (N)
- Rorippa palustris ssp. hispida (N)
- Rorippa sessiliflora (N)
- Rorippa sylvestris (I)
- Rosa arkansana var. suffulta (N)
- Rosa blanda var. blanda (N)
- Rosa canina (I)
- Rosa carolina var. carolina (N)
- Rosa centifolia (I)
- Rosa cinnamomea (I)
- Rosa eglanteria (I)
- Rosa gallica (I)
- Rosa majalis (I)
- Rosa micrantha (I)
- Rosa multiflora (I)
- Rosa nitida (N)
- Rosa × palustriformis (N)
- Rosa palustris (N)
- Rosa pimpinellifolia (I)
- Rosa × rudiuscula (N)
- Rosa rugosa (I)
- Rosa setigera var. setigera (N)
- Rosa setigera var. tomentosa (N)
- Rosa wichuraiana (I)
- Rotala ramosior (N)
- Rubus aboriginum (N)
- Rubus allegheniensis var. allegheniensis (N)
- Rubus allegheniensis var. gravesii (N)
- Rubus alumnus (N)
- Rubus argutus (N)
- Rubus armeniacus (I)
- Rubus baileyanus (N)
- Rubus bellobatus (N)
- Rubus canadensis (N)
- Rubus deamii (N)
- Rubus depavitus (N)
- Rubus fecundus (N)
- Rubus flagellaris (N)
- Rubus frondosus (N)
- Rubus hispidus (N)
- Rubus idaeus ssp. strigosus (N)
- Rubus idaeus ssp. idaeus (I)
- Rubus invisus (N)
- Rubus laciniatus (I)
- Rubus laudatus (N)
- Rubus meracus (N)
- Rubus michiganensis (N)
- Rubus multifer (N)
- Rubus occidentalis (N)
- Rubus odoratus var. odoratus (N)
- Rubus pensilvanicus (N)
- Rubus pergratus (N)
- Rubus philadelphicus (N)
- Rubus phoenicolasius (I)
- Rubus plicatifolius (N)
- Rubus prestonensis (N)
- Rubus pubescens var. pubescens (N)
- Rubus recurvans (N)
- Rubus recurvicaulis (N)
- Rubus roribaccus (N)
- Rubus rosa (N)
- Rubus setosus (N)
- Rubus suus (N)
- Rubus trivialis (N)
- Rubus uvidus (N)
- Rubus vagus (N)
- Rudbeckia fulgida var. deamii (N)
- Rudbeckia fulgida var. fulgida (N)
- Rudbeckia fulgida var. speciosa (N)
- Rudbeckia fulgida var. umbrosa (N)
- Rudbeckia grandiflora var. grandiflora (N)
- Rudbeckia hirta var. hirta (N)
- Rudbeckia hirta var. pulcherrima (N)
- Rudbeckia laciniata var. laciniata (N)
- Rudbeckia triloba var. triloba (N)
- Ruellia caroliniensis ssp. caroliniensis var. caroliniensis (N)
- Ruellia caroliniensis ssp. caroliniensis (N)
- Ruellia humilis (N)
- Ruellia strepens (N)
- Rumex acetosa (N)
- Rumex acetosa ssp. acetosa (I)
- Rumex acetosella (I)
- Rumex × acutus (I)
- Rumex × acutus (N)
- Rumex altissimus (N)
- Rumex conglomeratus (I)
- Rumex crispus ssp. crispus (I)
- Rumex maritimus (N)
- Rumex obtusifolius (I)
- Rumex orbiculatus var. borealis (N)
- Rumex orbiculatus var. orbiculatus (N)
- Rumex patientia (I)
- Rumex salicifolius var. mexicanus (N)
- Rumex verticillatus (N)
- Ruppia cirrhosa (N)
Read more about this topic: Flora Of Ohio