| R |
| Radiant Red water lily, Nymphaea 'Radiant Red' |
| Ragwort, Golden, Senecio aureus |
| Rainbow plant, Houttuynia cordata |
| Rainbows End rose, Rosa 'SAValife' |
| Ralph's Creeper rose, Rosa 'MORpapplay' |
| Ramps; Wild leek, Allium tricoccum |
| Ranunculus, Ranunculus |
| Raspberry, Purple flowering, Rubus odoratus |
| Rattle-snake plantain, Downy rattlesnake plantain, Goodyera pubescens |
| Rattlebush, Sesbania punicea |
| Rattlesnake fern, Botrychium virginianum |
| Rattlesnake master, Eryngium aquaticum |
| Rattlesnake root; Tall white lettuce, Prenanthes altissima |
| Rattlesnake weed, Hieracium venosum |
| Ravenna grass, Saccharum ravennae |
| Ray Davies water lily, Nymphaea 'Ray Davies' |
| Red Beach rose, Rosa |
| Red Bonica rose, Rosa 'Red Bonica' |
| Red Cascade rose, Rosa 'MOORcap' |
| Red cuphea, Cuphea llavea |
| Red elderberry, Sambucus pubens |
| Red Flower Carpet rose, Rosa 'Red Flower Carpet' |
| Red Fountain rose, Rosa 'Red Fountain' |
| Red hot poker, Kniphofia |
| Red Masterpiece rose, Rosa 'JACder' |
| Red Meidland rose, Rosa 'MELneble' |
| Red Provence rose, Rosa 'Red Provence' |
| Red Radiance rose, Rosa 'Red Radiance' |
| Red Ribbons rose, Rosa 'KORtemma' |
| Red Rose of Lancaster, Rosa 'Red Rose of Lancaster' |
| Red Rouge rose, Rosa 'Red Rouge' |
| Red ruellia, Ruellia elegans |
| Red Rugosa rose, Rosa rugosa rubra |
| Red Simplicity rose, Rosa 'JACsimpl' |
| Red valerian, Centranthus ruber |
| Red-leaved rose, Rosa |
| Redbay, Persea borbonia |
| Redbay, Swamp, Persea palustris |
| Redbay, Persea borbonia |
| Redbud, California, Cercis californica ssp. californica |
| Redbud, Chain flowered, Cercis racemosa |
| Redbud, Chinese, Cercis chinensis |
| Redbud, Chinese, Cercis chinensis |
| Redbud, Convey, Cercis canadensis 'Convey' |
| Redbud, Eastern, Cercis canadensis |
| Redbud, Giant, Cercis giganteta |
| Redbud, Mediterranean, Cercis siliquastrum |
| Redbud, Mexican, Cercis canadensis ssp. mexicana |
| Redbud, Oklahoma, Cercis canadensis ssp. retisus |
| Redbud, Texas, Cercis canadensis ssp. texensis |
| Redbud, Western, Cercis californica ssp. californica |
| Redbud, Cercis chingii |
| Redbud; Judas tree, Cercis canadensis |
| Redcedar, Southern, Juniperus virginiana var. silicicola |
| Redwood, Coastal, Sequoia sempervirens 'Adpressa' |
| Redwood, Dawn, Metasequio glyptostroboides |
| Redwood, Sierra, Sequsiadendron giaganteum |
| Redwood, Soquel, Sequoia sempervirens 'Soquel' |
| Redwood, Sequoia sempervirens |
| Regensberg rose, Rosa 'MACyoumis' |
| Reine Victoria rose, Rosa 'Reine Victoria' |
| Rene Andre rose, Rosa 'Rene Andre' |
| Resurrection fern, Polypodium polypodioides |
| Rhamnella, Rhamnella franguloides |
| Rhododendron, Carolina, Rhododendron carolinianum |
| Rhododendron, Carolina, Rhododendron carolinianum |
| Rhododendron, Catawba; Purple rhododendron, Rhododendron catawbiense |
| Rhododendron, Catawba; Purple rhododendron; Mountain rosebay, Rhododendron catawbiense |
| Rhododendron, Chapman's, Rhododendron minus var. chapmanii |
| Rhododendron, Chapman's, Rhododendron minus var. chapmanii |
| Rhododendron, Korean, Rhododendron mucronulatum |
| Rhododendron, Ramapo, Rhododendron 'Ramapo' |
| Rhododendron, Rosebay, Rhododendron maximum |
| Rhododendron, Rosebay; Max; White laurel, Rhododendron maximum |
| Rhododendron, Windbeam, Rhododendron 'Windbeam' |
| Rhododendron, Yak, Rhododendron yakusimanum |
| Rhonda rose, Rosa 'Rhonda' |
| Ribbon grass, Phalaris arundarinacea |
| Ribbon grass; Gardener's garters; Reed canary grass, Phalaris arundinaera |
| Rigid buckler fern, Dryopteris villarii |
| Rio Samba rose, Rosa 'JACrite' |
| Rise 'n' Shine rose, Rosa 'Rise 'n' Shine |
| River birch, Betula nigra |
| River fern; Southern shield fern; Southern maiden fern; Widespread maiden fern, Thelpteris kunthii; Thelypteris normalis |
| Roberta rose, Rosa 'AUSblush' |
| Robin des Bois rose, Rosa 'Robin des Bois' |
| Robin Hood rose, Rosa 'Robin Hood' |
| Robin-plantain, Erigeron pulchellus |
| Robusta rose, Rosa 'KORgosa' |
| Rock 'n' Roll rose, Rosa 'Rock 'n' Roll' |
| Rock sandwort, Arenaria stricta |
| Rockin Robin rose, Rosa 'WEKboroco' |
| Rocky Mountain garland, Clarkia hybrids |
| Rodgersia, Rodgersia spp. |
| Roman Holiday rose, Rosa 'LINro' |
| Rosa hugonis rose, Rosa hugonis |
| Rosa mundi rose, Rosa gallica versicolor |
| Rosa nitida rose, Rosa nitida |
| Rosa Richardii rose, Rosa richardii |
| Rosalyn Carter rose, Rosa 'Ruprins' |
| Rose Arey Hybrid water lily, Nymphaea 'Rose Arey' |
| Rose campion, Lychnis coronaria |
| Rose de Meaux, Rosa centifolia pompons |
| Rose de Rescht, Rosa 'Rose de Rescht' |
| Rose Gaujard, Rosa 'GAUmo' |
| Rose mallow, Hibiscus moscheutos |
| Rose of Castile, Rosa damascena bifera |
| Rose of the Tomb, Rosa 'Rose of The Tomb' |
| Rose, Apple, Rosa villosa |
| Rose, Carolina; Pasture rose, Rosa carolina |
| Rose, China, Rosa chinensis |
| Rose, Confederate; Cotton rose, Hibiscus mutabilis |
| Rose, Fairy, Rosa 'The Fairy' |
| Rose, Lenten; Helleborus; Christmas rose, Helleborus orientalis |
| Rose, Memorial, Rosa wichuraiana |
| Rose, Memorial, Rosa wichuraiana |
| Rose, Petite Pink Scotch, Rosa x 'Petite Pink' |
| Rose, Rugosa, Rosa rugosa |
| Rose, Swamp, Rosa palustris |
| Rose, Virginia, Rosa virginiana |
| Rose-mallow, Swamp, Hibiscus palustris |
| Rose-of-sharon, Blue Bird, Hibiscus syriacus 'Blue Bird' |
| Rose-of-sharon, Diana, Hibiscus syriacus 'Diana' |
| Rose-of-sharon, Hibiscus syriacus |
| Rosemary, Cumberland, Conradina verticillata |
| Rosemary, Florida; Sandhill rosemary, Ceratiola ericoides |
| Rosemary, Rosemaryinus officinalis |
| Rosemary, Rosmarinus officinalis |
| Rosennymphe water lily, Nymphaea 'Rosennymphe' |
| Rosie O'Donnel rose, Rosa 'WEKwinwin' |
| Rosinweed, Silphinum integrifolium |
| Rosy Morn water lily, Nymphaea 'Rosy Morn' |
| Royal Amethyst rose, Rosa 'DEVmorada' |
| Royal Bonica Meidland rose, Rosa 'MELmodac' |
| Royal fern; Flowering fern, Osmunda regallis |
| Royal Sunset rose, Rosa 'Royal Sunset' |
| Rubber tree, Hardy, Eucommia ulmoides |
| Rubra rose, Rosa 'Rubra' |
| Rubus, Taiwanese creeping; Creeping bramble, Rubus calcyinoiden |
| Rue, Goat's, Tephrosia virginiana |
| Rue, Meadow, Thalictrum revolutum |
| Rue, Meadow; Columbine meadow rue, Thalictrum aquilegifolium |
| Rue, Purple meadow, Thalictrum dasycarpum |
| Rue, Ruta graveolens |
| Rush, Corkscrew, Juncus effusus 'Spiralis' |
| Rush, Giant variegated Mediterranean, Arundo domax 'Variegata' |
| Rush, Green bull, Juncus effusus |
| Rush, Japanese mat, Juncus effusus |
| Rush, Japanese, Acorus gramimineus |
| Rush, Soft, Juncus effusus |
| Rush, Souring, Equisetum hyemale |
| Rush, Spike, Eleocharis montevidensis |
| Rush, Square, Eleocharis quadrangulata |
| Rush, Variegated, Baumea rubiginosa 'Variegata' |
| Rush, Zebra, Scripus laustris subsp. tabernaemontani 'Zebrinus' |
| Russian olive, Eleagnus angustifolia |