| Rudbeckia columnaris Pursh | Ratibida columnifera (Nutt.) Wooton & Standl. | | | Rudbeckia columnarisPursh | Ratibida columnifera(Nutt.) Wooton & Standl. |
| Rudbeckia columnifera Nutt. | Ratibida columnifera (Nutt.) Wooton & Standl. | | | Rudbeckia columniferaNutt. | Ratibida columnifera(Nutt.) Wooton & Standl. |
| Rudbeckia hirta L. | | a | | Rudbeckia hirtaL. | |
| Rudbeckia laciniata L. | | a | | Rudbeckia laciniataL. | |
| Rudbeckia purpurea L. | Echinacea purpurea (L.) Moench | | | Rudbeckia purpureaL. | Echinacea purpurea(L.) Moench |
| Rudbeckia speciosa Wender. | Rudbeckia fulgida Aiton var. speciosa (Wender.) Perdue | | | Rudbeckia speciosaWender. | Rudbeckia fulgidaAiton var.speciosa (Wender.) Perdue |
| Rudbeckia grandiflora (Sweet) C. C. Gmel. ex DC. | | a | | Rudbeckia grandiflora(Sweet) C. C. Gmel. ex DC. | |
| Rudbeckia angustifolia (L.) L. | Helianthus angustifolius L. | | | Rudbeckia angustifolia(L.) L. | Helianthus angustifoliusL. |
| Rudbeckia fulgida Aiton var. speciosa (Wender.) Perdue | | a | i | Rudbeckia fulgidaAiton var.speciosa (Wender.) Perdue | |
| Rudbeckia spp. | | a | | Rudbeckia spp. | |
| Rudbeckia fulgida Aiton | | a | | Rudbeckia fulgidaAiton | |
| Rudbeckia fulgida Aiton var. fulgida | | a | i | Rudbeckia fulgidaAiton var.fulgida | |
| Rudbeckia amplexicaulis Vahl | | a | | Rudbeckia amplexicaulisVahl | |
| Rudbeckia bicolor Nutt. | Rudbeckia hirta L. var. pulcherrima Farw. | | | Rudbeckia bicolorNutt. | Rudbeckia hirtaL. var.pulcherrima Farw. |
| Rudbeckia gloriosa hort. | Rudbeckia fulgida Aiton var. speciosa (Wender.) Perdue | | | Rudbeckia gloriosahort. | Rudbeckia fulgidaAiton var.speciosa (Wender.) Perdue |
| Rudbeckia pallida Nutt. | Echinacea pallida (Nutt.) Nutt. | | | Rudbeckia pallidaNutt. | Echinacea pallida(Nutt.) Nutt. |
| Rudbeckia occidentalis Nutt. | | a | | Rudbeckia occidentalisNutt. | |
| Rudbeckia porteri A. Gray | Helianthus porteri (A. Gray) Pruski | | | Rudbeckia porteriA. Gray | Helianthus porteri(A. Gray) Pruski |
| Rudbeckia radula Pursh | Helianthus radula (Pursh) Torr. & A. Gray | | | Rudbeckia radulaPursh | Helianthus radula(Pursh) Torr. & A. Gray |
| Rudbeckia subtomentosa Pursh | | a | | Rudbeckia subtomentosaPursh | |
| Rudbeckia triloba L. | | a | | Rudbeckia trilobaL. | |
| Rudbeckia texana (Perdue) P. B. Cox & Urbatsch | | a | | Rudbeckia texana(Perdue) P. B. Cox & Urbatsch | |
| Rudbeckia nitida Nutt. var. texana Perdue | Rudbeckia texana (Perdue) P. B. Cox & Urbatsch | | i | Rudbeckia nitidaNutt. var.texana Perdue | Rudbeckia texana(Perdue) P. B. Cox & Urbatsch |
| Rudbeckia scabrifolia L. E. Br. | | a | | Rudbeckia scabrifoliaL. E. Br. | |
| Rudbeckia auriculata (Perdue) Kral | | a | | Rudbeckia auriculata(Perdue) Kral | |
| Rudbeckia fulgida Aiton var. auriculata Perdue | Rudbeckia auriculata (Perdue) Kral | | i | Rudbeckia fulgidaAiton var.auriculata Perdue | Rudbeckia auriculata(Perdue) Kral |
| Rudbeckia alpicola Piper | | a | | Rudbeckia alpicolaPiper | |
| Rudbeckia californica A. Gray | | a | | Rudbeckia californicaA. Gray | |
| Rudbeckia maxima Nutt. | | a | | Rudbeckia maximaNutt. | |
| Rudbeckia graminifolia (Torr. & A. Gray) C. L. Boynton & Beadle | | a | | Rudbeckia graminifolia(Torr. & A. Gray) C. L. Boynton & Beadle | |
| Rudbeckia heliopsidis Torr. & A. Gray | | a | | Rudbeckia heliopsidisTorr. & A. Gray | |
| Rudbeckia missouriensis Engelm. ex C. L. Boynton & Beadle | | a | | Rudbeckia missouriensisEngelm. ex C. L. Boynton & Beadle | |
| Rudbeckia mohrii A. Gray | | a | | Rudbeckia mohriiA. Gray | |
| Rudbeckia mollis Elliott | | a | | Rudbeckia mollisElliott | |
| Rudbeckia glaucescens Eastw. | | a | | Rudbeckia glaucescensEastw. | |
| Rudbeckia klamathensis P. B. Cox & Urbatsch | | a | | Rudbeckia klamathensisP. B. Cox & Urbatsch | |
| Rudbeckia nitida Nutt. | | a | | Rudbeckia nitidaNutt. | |
| Rudbeckia californica A. Gray var. glauca S. F. Blake | Rudbeckia glaucescens Eastw. | | i | Rudbeckia californicaA. Gray var.glauca S. F. Blake | Rudbeckia glaucescensEastw. |
| Rudbeckia californica A. Gray var. intermedia Perdue | Rudbeckia klamathensis P. B. Cox & Urbatsch | | i | Rudbeckia californicaA. Gray var.intermedia Perdue | Rudbeckia klamathensisP. B. Cox & Urbatsch |
| Rudbeckia fulgida Aiton var. deamii (S. F. Blake) Perdue | | a | i | Rudbeckia fulgidaAiton var.deamii (S. F. Blake) Perdue | |
| Rudbeckia fulgida Aiton var. sullivantii (C. L. Boynton & Beadle) Cronquist | Rudbeckia fulgida Aiton var. speciosa (Wender.) Perdue | | i | Rudbeckia fulgidaAiton var.sullivantii (C. L. Boynton & Beadle) Cronquist | Rudbeckia fulgidaAiton var.speciosa (Wender.) Perdue |
| Rudbeckia fulgida Aiton var. umbrosa (C. L. Boynton & Beadle) Cronquist | | a | i | Rudbeckia fulgidaAiton var.umbrosa (C. L. Boynton & Beadle) Cronquist | |
| Rudbeckia fulgida Aiton var. palustris (Eggert ex C. L. Boynton & Beadle) Perdue | | a | i | Rudbeckia fulgidaAiton var.palustris (Eggert ex C. L. Boynton & Beadle) Perdue | |
| Rudbeckia fulgida Aiton var. spathulata (Michx.) Perdue | Rudbeckia fulgida Aiton var. fulgida | | i | Rudbeckia fulgidaAiton var.spathulata (Michx.) Perdue | Rudbeckia fulgidaAiton var.fulgida |
| Rudbeckia deamii S. F. Blake | Rudbeckia fulgida Aiton var. deamii (S. F. Blake) Perdue | | | Rudbeckia deamiiS. F. Blake | Rudbeckia fulgidaAiton var.deamii (S. F. Blake) Perdue |
| Rudbeckia sullivantii C. L. Boynton & Beadle | Rudbeckia fulgida Aiton var. speciosa (Wender.) Perdue | | | Rudbeckia sullivantiiC. L. Boynton & Beadle | Rudbeckia fulgidaAiton var.speciosa (Wender.) Perdue |
| Rudbeckia palustris Eggert ex C. L. Boynton & Beadle | Rudbeckia fulgida Aiton var. palustris (Eggert ex C. L. Boynton & Beadle) Perdue | | | Rudbeckia palustrisEggert ex C. L. Boynton & Beadle | Rudbeckia fulgidaAiton var.palustris (Eggert ex C. L. Boynton & Beadle) Perdue |
| Rudbeckia spathulata Michx. | Rudbeckia fulgida Aiton var. fulgida | | | Rudbeckia spathulataMichx. | Rudbeckia fulgidaAiton var.fulgida |
| Rudbeckia umbrosa C. L. Boynton & Beadle | Rudbeckia fulgida Aiton var. umbrosa (C. L. Boynton & Beadle) Cronquist | | | Rudbeckia umbrosaC. L. Boynton & Beadle | Rudbeckia fulgidaAiton var.umbrosa (C. L. Boynton & Beadle) Cronquist |
| Rudbeckia grandiflora (Sweet) C. C. Gmel. ex DC. var. grandiflora | | a | i | Rudbeckia grandiflora(Sweet) C. C. Gmel. ex DC. var.grandiflora | |
| Rudbeckia grandiflora (Sweet) C. C. Gmel. ex DC. var. alismifolia (Torr. & A. Gray) Cronquist | | a | i | Rudbeckia grandiflora(Sweet) C. C. Gmel. ex DC. var.alismifolia (Torr. & A. Gray) Cronquist | |
| Rudbeckia alismifolia Torr. & A. Gray | Rudbeckia grandiflora (Sweet) C. C. Gmel. ex DC. var. alismifolia (Torr. & A. Gray) Cronquist | | | Rudbeckia alismifoliaTorr. & A. Gray | Rudbeckia grandiflora(Sweet) C. C. Gmel. ex DC. var.alismifolia (Torr. & A. Gray) Cronquist |
| Rudbeckia hirta L. var. hirta | | a | i | Rudbeckia hirtaL. var.hirta | |
| Rudbeckia hirta L. var. pulcherrima Farw. | | a | i | Rudbeckia hirtaL. var.pulcherrima Farw. | |
| Rudbeckia hirta L. var. corymbifera Fernald | Rudbeckia hirta L. var. pulcherrima Farw. | | i | Rudbeckia hirtaL. var.corymbifera Fernald | Rudbeckia hirtaL. var.pulcherrima Farw. |
| Rudbeckia hirta L. var. angustifolia (T. V. Moore) Perdue | | a | i | Rudbeckia hirtaL. var.angustifolia (T. V. Moore) Perdue | |
| Rudbeckia hirta L. var. floridana (T. V. Moore) Perdue | | a | i | Rudbeckia hirtaL. var.floridana (T. V. Moore) Perdue | |
| Rudbeckia laciniata L. var. ampla (A. Nelson) Cronquist | | a | i | Rudbeckia laciniataL. var.ampla (A. Nelson) Cronquist | |
| Rudbeckia laciniata L. var. bipinnata Perdue | | a | i | Rudbeckia laciniataL. var.bipinnata Perdue | |
| Rudbeckia laciniata L. var. gaspereauensis Fernald | Rudbeckia laciniata L. var. laciniata | | i | Rudbeckia laciniataL. var.gaspereauensis Fernald | Rudbeckia laciniataL. var.laciniata |
| Rudbeckia laciniata L. var. humilis A. Gray | | a | i | Rudbeckia laciniataL. var.humilis A. Gray | |
| Rudbeckia laciniata L. var. laciniata | | a | i | Rudbeckia laciniataL. var.laciniata | |
| Rudbeckia floridana T. V. Moore var. angustifolia T. V. Moore | Rudbeckia hirta L. var. angustifolia (T. V. Moore) Perdue | | i | Rudbeckia floridanaT. V. Moore var.angustifolia T. V. Moore | Rudbeckia hirtaL. var.angustifolia (T. V. Moore) Perdue |
| Rudbeckia floridana T. V. Moore | Rudbeckia hirta L. var. floridana (T. V. Moore) Perdue | | | Rudbeckia floridanaT. V. Moore | Rudbeckia hirtaL. var.floridana (T. V. Moore) Perdue |
| Rudbeckia ampla A. Nelson | Rudbeckia laciniata L. var. ampla (A. Nelson) Cronquist | | | Rudbeckia amplaA. Nelson | Rudbeckia laciniataL. var.ampla (A. Nelson) Cronquist |
| Rudbeckia laciniata L. var. digitata (Mill.) Fiori | Rudbeckia laciniata L. var. humilis A. Gray | | i | Rudbeckia laciniataL. var.digitata (Mill.) Fiori | Rudbeckia laciniataL. var.humilis A. Gray |
| Rudbeckia digitata Mill. | Rudbeckia laciniata L. var. humilis A. Gray | | | Rudbeckia digitataMill. | Rudbeckia laciniataL. var.humilis A. Gray |
| Rudbeckia atrorubens Nutt. | Echinacea atrorubens (Nutt.) Nutt. | | | Rudbeckia atrorubensNutt. | Echinacea atrorubens(Nutt.) Nutt. |
| Rudbeckia tagetes E. James | Ratibida tagetes (E. James) Barnhart | | | Rudbeckia tagetesE. James | Ratibida tagetes(E. James) Barnhart |
| Rudbeckia laciniata L. var. heterophylla (Torr. & A. Gray) Fernald & B. G. Schub. | | a | i | Rudbeckia laciniataL. var.heterophylla (Torr. & A. Gray) Fernald & B. G. Schub. | |
| Rudbeckia heterophylla Torr. & A. Gray | Rudbeckia laciniata L. var. heterophylla (Torr. & A. Gray) Fernald & B. G. Schub. | | | Rudbeckia heterophyllaTorr. & A. Gray | Rudbeckia laciniataL. var.heterophylla (Torr. & A. Gray) Fernald & B. G. Schub. |
| Rudbeckia occidentalis Nutt. var. alpicola (Piper) Cronquist | Rudbeckia alpicola Piper | | i | Rudbeckia occidentalisNutt. var.alpicola (Piper) Cronquist | Rudbeckia alpicolaPiper |
| Rudbeckia montana A. Gray | | a | | Rudbeckia montanaA. Gray | |
| Rudbeckia occidentalis Nutt. var. montana (A. Gray) Perdue | Rudbeckia montana A. Gray | | i | Rudbeckia occidentalisNutt. var.montana (A. Gray) Perdue | Rudbeckia montanaA. Gray |
| Rudbeckia triloba L. var. triloba | | a | i | Rudbeckia trilobaL. var.triloba | |
| Rudbeckia triloba L. var. pinnatiloba Torr. & A. Gray | | a | i | Rudbeckia trilobaL. var.pinnatiloba Torr. & A. Gray | |
| Rudbeckia triloba L. var. rupestris (Chick.) A. Gray | | a | i | Rudbeckia trilobaL. var.rupestris (Chick.) A. Gray | |
| Rudbeckia rupestris Chick. | Rudbeckia triloba L. var. rupestris (Chick.) A. Gray | | | Rudbeckia rupestrisChick. | Rudbeckia trilobaL. var.rupestris (Chick.) A. Gray |
| Rudbeckia californica A. Gray var. californica | Rudbeckia californica A. Gray | | i | Rudbeckia californicaA. Gray var.californica | Rudbeckia californicaA. Gray |
| Rudbeckia floridana T. V. Moore var. floridana | Rudbeckia hirta L. var. floridana (T. V. Moore) Perdue | | i | Rudbeckia floridanaT. V. Moore var.floridana | Rudbeckia hirtaL. var.floridana (T. V. Moore) Perdue |
| Rudbeckia nitida Nutt. var. nitida | Rudbeckia nitida Nutt. | | i | Rudbeckia nitidaNutt. var.nitida | Rudbeckia nitidaNutt. |
| Rudbeckia occidentalis Nutt. var. occidentalis | Rudbeckia occidentalis Nutt. | | i | Rudbeckia occidentalisNutt. var.occidentalis | Rudbeckia occidentalisNutt. |