Contents: Preface. Acknowledgements. Introduction. Monographs. 1. Rabdosia 2. Radermachera 3. Randia 4. Ranunculus 5. Rapanea 6. Raphanus 7. Rauvolfia 8. Ravenala 9. Ravenia 10. Reidia 11. Reinwardtia 12. Reinwardtiodendron 13. Remusatia 14. Rhamnus 15. Rhaphidophora 16. Rhapis 17. Rhazya 18. Rheum 19. Rhinacanthus 20. Rhizophora 21. Rhodiola 22. Rhododendron 23. Rhodomyrtus 24. Rhus 25. Rhynchosia 26. Rhynchostylis 27. Rhynchotechum 28. Ribes 29. Richardia 30. Ricinus 31. Rinorea 32. Rivea 33. Rivina 34. Robinia 35. Roegneria 36. Rorippa 37. Rosa 38. Roscoea 39. Rosmarinus 40. Rostellularia 41. Rotala 42. Rothia 43. Rothmannia 44. Rottboellia 45. Rotula 46. Rourea 47. Roylea 48. Roystonea 49. Rubia 50. Rubus 51. Rudbeckia 52. Ruellia 53. Rumex 54. Rungia 55. Ruscus 56. Russelia 57. Ruta. Appendices. Indices. Plant Genera Included in Earlier Volumes.