| Rhododendron albrechtii Maxim. | | a | | Rhododendron albrechtiiMaxim. | |
| Rhododendron amagianum (Makino) H. Hara | | a | | Rhododendron amagianum(Makino) H. Hara | |
| Rhododendron austrokiusianum Hatus. | Rhododendron obtusum (Lindl.) Planch. | | | Rhododendron austrokiusianumHatus. | Rhododendron obtusum(Lindl.) Planch. |
| Rhododendron balsaminiflorum Carriere | Rhododendron indicum (L.) Sweet | | | Rhododendron balsaminiflorumCarriere | Rhododendron indicum(L.) Sweet |
| Rhododendron decandrum (Makino) Makino | | a | | Rhododendron decandrum(Makino) Makino | |
| Rhododendron dilatatum Miq. | | a | | Rhododendron dilatatumMiq. | |
| Rhododendron farrerae Tate ex Sweet | | a | | Rhododendron farreraeTate ex Sweet | |
| Rhododendron indicum (L.) Sweet | | a | | Rhododendron indicum(L.) Sweet | |
| Rhododendron indicum (L.) Sweet var. eriocarpum Hayata | Rhododendron eriocarpum (Hayata) Nakai | | i | Rhododendron indicum(L.) Sweet var.eriocarpum Hayata | Rhododendron eriocarpum(Hayata) Nakai |
| Rhododendron indicum (L.) Sweet var. phoeniceum Sweet | Rhododendron ×pulchrum Sweet | | i | Rhododendron indicum(L.) Sweet var.phoeniceum Sweet | Rhododendron pulchrumSweet |
| Rhododendron kaempferi Planch. | | a | | Rhododendron kaempferiPlanch. | |
| Rhododendron kaempferi Planch. f. album Nakai | Rhododendron kaempferi Planch. | | i | Rhododendron kaempferiPlanch. f. album Nakai | Rhododendron kaempferiPlanch. |
| Rhododendron kanehirae E. H. Wilson | | a | | Rhododendron kanehiraeE. H. Wilson | |
| Rhododendron kiusianum Makino | | a | | Rhododendron kiusianumMakino | |
| Rhododendron kiyosumense (Makino) Makino | | a | | Rhododendron kiyosumense(Makino) Makino | |
| Rhododendron komiyamae Makino | | a | | Rhododendron komiyamaeMakino | |
| Rhododendron lasiostylum Hayata | | a | | Rhododendron lasiostylumHayata | |
| Rhododendron leptothrium Balf. f. & Forrest | | a | | Rhododendron leptothriumBalf. f. & Forrest | |
| Rhododendron linearifolium Siebold & Zucc. | Rhododendron stenopetalum (Hogg) Mabb. | | | Rhododendron linearifoliumSiebold & Zucc. | Rhododendron stenopetalum(Hogg) Mabb. |
| Rhododendron linearifolium Siebold & Zucc. var. macrosepalum (Maxim.) Makino | Rhododendron stenopetalum (Hogg) Mabb. | | i | Rhododendron linearifoliumSiebold & Zucc. var.macrosepalum (Maxim.) Makino | Rhododendron stenopetalum(Hogg) Mabb. |
| Rhododendron eriocarpum (Hayata) Nakai | | a | | Rhododendron eriocarpum(Hayata) Nakai | |
| Rhododendron macrosepalum Maxim. | Rhododendron stenopetalum (Hogg) Mabb. | | | Rhododendron macrosepalumMaxim. | Rhododendron stenopetalum(Hogg) Mabb. |
| Rhododendron mariesii Hemsl. & E. H. Wilson | | a | | Rhododendron mariesiiHemsl. & E. H. Wilson | |
| Rhododendron maxwellii Millais | Rhododendron ×pulchrum Sweet | | | Rhododendron maxwelliiMillais | Rhododendron pulchrumSweet |
| Rhododendron mayebarae Nakai & H. Hara | | a | | Rhododendron mayebaraeNakai & H. Hara | |
| Rhododendron microphyton Franch. | | a | | Rhododendron microphytonFranch. | |
| Rhododendron mucronatum (Blume) G. Don | | a | | Rhododendron mucronatum(Blume) G. Don | |
| Rhododendron mucronatum (Blume) G. Don var. ripense (Makino) E. H. Wilson | | a | i | Rhododendron mucronatum(Blume) G. Don var.ripense (Makino) E. H. Wilson | |
| Rhododendron nakaharae Hayata | | a | | Rhododendron nakaharaeHayata | |
| Rhododendron nipponicum Matsum. | | a | | Rhododendron nipponicumMatsum. | |
| Rhododendron nudipes Nakai | | a | | Rhododendron nudipesNakai | |
| Rhododendron obtusum (Lindl.) Planch. | | a | | Rhododendron obtusum(Lindl.) Planch. | |
| Rhododendron obtusum (Lindl.) Planch. f. amoenum (Lindl.) E. H. Wilson | Rhododendron obtusum (Lindl.) Planch. | | i | Rhododendron obtusum(Lindl.) Planch. f. amoenum (Lindl.) E. H. Wilson | Rhododendron obtusum(Lindl.) Planch. |
| Rhododendron obtusum (Lindl.) Planch. var. japonicum (Maxim.) Kitam. | Rhododendron kiusianum Makino | | i | Rhododendron obtusum(Lindl.) Planch. var.japonicum (Maxim.) Kitam. | Rhododendron kiusianumMakino |
| Rhododendron obtusum (Lindl.) Planch. var. kaempferi (Planch.) E. H. Wilson | Rhododendron kaempferi Planch. | | i | Rhododendron obtusum(Lindl.) Planch. var.kaempferi (Planch.) E. H. Wilson | Rhododendron kaempferiPlanch. |
| Rhododendron oldhamii Maxim. | | a | | Rhododendron oldhamiiMaxim. | |
| Rhododendron omurasaki Makino | Rhododendron ×pulchrum Sweet | | | Rhododendron omurasakiMakino | Rhododendron pulchrumSweet |
| Rhododendron ovatum (Lindl.) Maxim. | | a | | Rhododendron ovatum(Lindl.) Maxim. | |
| Rhododendron pentaphyllum Maxim. | | a | | Rhododendron pentaphyllumMaxim. | |
| Rhododendron pentaphyllum Maxim. var. nikoense Komatsu | | a | i | Rhododendron pentaphyllumMaxim. var.nikoense Komatsu | |
| Rhododendron phoeniceum (Sweet) G. Don | Rhododendron ×pulchrum Sweet | | | Rhododendron phoeniceum(Sweet) G. Don | Rhododendron pulchrumSweet |
| Rhododendron phoeniceum (Sweet) G. Don var. calycinum (Lindl.) E. H. Wilson | Rhododendron ×pulchrum Sweet | | i | Rhododendron phoeniceum(Sweet) G. Don var.calycinum (Lindl.) E. H. Wilson | Rhododendron pulchrumSweet |
| Rhododendron ×pulchrum Sweet | | a | | Rhododendron pulchrumSweet | |
| Rhododendron ×pulchrum Sweet var. calycinum (Lindl.) Rehder | Rhododendron ×pulchrum Sweet | | i | Rhododendron pulchrumSweet var.calycinum (Lindl.) Rehder | Rhododendron pulchrumSweet |
| Rhododendron ×pulchrum Sweet var. maxwellii Rehder | Rhododendron ×pulchrum Sweet | | i | Rhododendron pulchrumSweet var.maxwellii Rehder | Rhododendron pulchrumSweet |
| Rhododendron ×pulchrum Sweet var. phoeniceum (Sweet) Rehder | Rhododendron ×pulchrum Sweet | | i | Rhododendron pulchrumSweet var.phoeniceum (Sweet) Rehder | Rhododendron pulchrumSweet |
| Rhododendron quinquefolium Bisset & S. Moore | | a | | Rhododendron quinquefoliumBisset & S. Moore | |
| Rhododendron reticulatum D. Don ex G. Don | | a | | Rhododendron reticulatumD. Don ex G. Don | |
| Rhododendron rhombicum Miq. | Rhododendron reticulatum D. Don ex G. Don | | | Rhododendron rhombicumMiq. | Rhododendron reticulatumD. Don ex G. Don |
| Rhododendron ripense Makino | Rhododendron mucronatum (Blume) G. Don var. ripense (Makino) E. H. Wilson | | | Rhododendron ripenseMakino | Rhododendron mucronatum(Blume) G. Don var.ripense (Makino) E. H. Wilson |
| Rhododendron rubropilosum Hayata | | a | | Rhododendron rubropilosumHayata | |
| Rhododendron rufohirtum Hand.-Mazz. | | a | | Rhododendron rufohirtumHand.-Mazz. | |
| Rhododendron sanctum Nakai | | a | | Rhododendron sanctumNakai | |
| Rhododendron sataense Nakai | Rhododendron obtusum (Lindl.) Planch. | | | Rhododendron sataenseNakai | Rhododendron obtusum(Lindl.) Planch. |
| Rhododendron scabrum G. Don | | a | | Rhododendron scabrumG. Don | |
| Rhododendron schlippenbachii Maxim. | | a | | Rhododendron schlippenbachiiMaxim. | |
| Rhododendron semibarbatum Maxim. | | a | | Rhododendron semibarbatumMaxim. | |
| Rhododendron serpyllifolium (A. Gray) Miq. | | a | | Rhododendron serpyllifolium(A. Gray) Miq. | |
| Rhododendron shikokianum Makino, nom. inval. | Rhododendron weyrichii Maxim. | | | Rhododendron shikokianumMakino, nom. inval. | Rhododendron weyrichiiMaxim. |
| Rhododendron simsii Planch. | | a | | Rhododendron simsiiPlanch. | |
| Rhododendron sublanceolatum Miq. | Rhododendron scabrum G. Don | | | Rhododendron sublanceolatumMiq. | Rhododendron scabrumG. Don |
| Rhododendron subsessile Rendle | | a | | Rhododendron subsessileRendle | |
| Rhododendron tanakae (Maxim.) Ohwi | Rhododendron tsusiophyllum Sugim. | | | Rhododendron tanakae(Maxim.) Ohwi | Rhododendron tsusiophyllumSugim. |
| Rhododendron tashiroi Maxim. | | a | | Rhododendron tashiroiMaxim. | |
| Rhododendron tosaense Makino | | a | | Rhododendron tosaenseMakino | |
| Rhododendron tschonoskii Maxim. | | a | | Rhododendron tschonoskiiMaxim. | |
| Rhododendron weyrichii Maxim. | | a | | Rhododendron weyrichiiMaxim. | |
| Rhododendron yedoense Maxim. | | a | | Rhododendron yedoenseMaxim. | |
| Rhododendron yedoense Maxim. var. poukhanense (H. Lev.) Nakai | | a | i | Rhododendron yedoenseMaxim. var.poukhanense (H. Lev.) Nakai | |
| Rhododendron vaseyi A. Gray | | a | | Rhododendron vaseyiA. Gray | |
| Rhododendron tsusiophyllum Sugim. | | a | | Rhododendron tsusiophyllumSugim. | |
| Rhododendron dauricum L. var. sempervirens Sims | Rhododendron ledebourii Pojark. | | i | Rhododendron dauricumL. var.sempervirens Sims | Rhododendron ledebouriiPojark. |
| Rhododendron albiflorum Hook. | | a | | Rhododendron albiflorumHook. | |
| Rhododendron poukhanense H. Lev. | Rhododendron yedoense Maxim. var. poukhanense (H. Lev.) Nakai | | | Rhododendron poukhanenseH. Lev. | Rhododendron yedoenseMaxim. var.poukhanense (H. Lev.) Nakai |
| Rhododendron yedoense Maxim. var. yedoense | | a | i | Rhododendron yedoenseMaxim. var.yedoense | |
| Rhododendron mucronatum (Blume) G. Don var. mucronatum | | a | i | Rhododendron mucronatum(Blume) G. Don var.mucronatum | |
| Rhododendron indicum (L.) Sweet f. japonicum Maxim. | Rhododendron kiusianum Makino | | i | Rhododendron indicum(L.) Sweet f. japonicum Maxim. | Rhododendron kiusianumMakino |
| Rhododendron dilatatum Miq. var. decandrum Makino | Rhododendron decandrum (Makino) Makino | | i | Rhododendron dilatatumMiq. var.decandrum Makino | Rhododendron decandrum(Makino) Makino |
| Rhododendron ledebourii Pojark. | | a | | Rhododendron ledebouriiPojark. | |
| Rhododendron ×tectum Koidz. | | a | | Rhododendron tectumKoidz. | |
| Rhododendron wadanum Makino | | a | | Rhododendron wadanumMakino | |
| Rhododendron benhallii Craven | | a | | Rhododendron benhalliiCraven | |
| Rhododendron menziesii Craven | | a | | Rhododendron menziesiiCraven | |
| Rhododendron menziesii Craven subsp. glabellum (A. Gray) Craven | | a | i | Rhododendron menziesiiCraven subsp. glabellum (A. Gray) Craven | |
| Rhododendron menziesii Craven subsp. menziesii | | a | i | Rhododendron menziesiiCraven subsp. menziesii | |
| Rhododendron multiflorum (Maxim.) Craven var. purpureum (Makino) Craven | | a | i | Rhododendron multiflorum(Maxim.) Craven var.purpureum (Makino) Craven | |
| Rhododendron multiflorum (Maxim.) Craven f. bicolor (Makino) Craven | | a | i | Rhododendron multiflorum(Maxim.) Craven f. bicolor (Makino) Craven | |
| Rhododendron multiflorum (Maxim.) Craven | | a | | Rhododendron multiflorum(Maxim.) Craven | |
| Rhododendron pentandrum (Maxim.) Craven | | a | | Rhododendron pentandrum(Maxim.) Craven | |
| Rhododendron pilosum (Michx.) Craven | | a | | Rhododendron pilosum(Michx.) Craven | |
| Rhododendron kroniae Craven | | a | | Rhododendron kroniaeCraven | |
| Rhododendron stenopetalum (Hogg) Mabb. | | a | | Rhododendron stenopetalum(Hogg) Mabb. | |
| Rhododendron simsii Planch. var. simsii | | a | i | Rhododendron simsiiPlanch. var.simsii | |
| Rhododendron simsii Planch. var. mesembrinum Rehder | | a | i | Rhododendron simsiiPlanch. var.mesembrinum Rehder | |
| Rhododendron indicum Sweet var. ignescens Sweet | Rhododendron simsii Planch. var. simsii | | i | Rhododendron indicumSweet var.ignescens Sweet | Rhododendron simsiiPlanch. var.simsii |
| Rhododendron indicum Sweet var. simsii (Planch.) Maxim. | Rhododendron simsii Planch. var. simsii | | i | Rhododendron indicumSweet var.simsii (Planch.) Maxim. | Rhododendron simsiiPlanch. var.simsii |