Rhodohypoxis baurii Rhodoleia championii
Rhodomyrtus tomentosa Rhodophiala bifida
Rhodotypos scandens Rhodotypos scandens 'Black Jet Bead'
Rhopalostylis baueri Rhopalostylis sapida
Rhus aromatica Rhus aromatica 'Green Globe'
Rhus aromatica 'Gro-low' Rhus chinensis
Rhus chinensis 'September Beauty' Rhus copallina
Rhus copallina var. latifolia Rhus copallina var. latifolia 'Morton (Prairie Flame™)'
Rhus glabra Rhus integrifolia
Rhus lancea Rhus ovata
Rhus trilobata Rhus typhina
Rhus typhina 'Bailtiger (Tiger Eyes®)' Rhus typhina 'Lanciniata'
Rhyncholaelia digbyana Rhyncholaelia glauca
Ribes alpinum Ribes alpinum 'Green Mound'
Ribes alpinum 'Spreg (Green Jeans™)' Ribes aureum
Ribes aureum var. gracillimum Ribes malvaceum 'Wunderlich'
Ribes malvaceum var. viridiflorum Ribes nigrum 'Boscoop Giant'
Ribes sanguineum 'Brocklebankii' Ribes sanguineum 'King Edward VII'
Ribes sanguineum 'Pokie Pink' Ribes sanguineum var. glutinosum
Ribes sanguineum var. glutinosum 'Joyce Rose' Ribes silvestre 'Red Lake'
Ribes silvestre 'White Grape' Ribes speciosum
Ribes uva-crispa Ribes uva-crispa 'Pixwell'
Ribes viburnifolium Ricinus communis
Ricinus communis 'Carmencita' Ricinus communis 'Impala'
Ricinus communis 'Zanzibariensis' Rigidella orthantha
Robinia x ambigua 'Idahoensis' Robinia hispida
Robinia x margaretta 'Idaho' Robinia neomexicana
Robinia pseudoacacia Robinia pseudoacacia 'Aurea'
Robinia pseudoacacia 'Frisia' Robinia pseudoacacia 'Purple Robe'
Robinia pseudoacacia 'Tortuosa' Rodgersia aesculifolia
Rodgersia henrici Roldana petasitis
Romneya coulteri Romneya coulteri var. trichocalyx
Rondeletia leucophylla