• Ranunculus trichophyllus Water-crowfoot, Three-leaved
  
• Raphanus raphanistrum Wild Radish
  
• Reseda luteola Weld
  
• Rhamnus cathartica Buckthorn
  
• Rhinanthus minor Yellow Rattle
  
• Rhododendron ponticum Rhododendron
  
• Ribes nigrum Black Currant
  
• Ribes uva-crispa Gooseberry
  
• Rorippa amphibia Great Yellow-cress
  
• Rorippa islandica Northern Yellow-cress
  
• Rorippa microphylla Narrow-fruited Water-cress
  
• Rorippa nasturtium-aquaticum Water-cress
  
• Rorippa palustris Marsh Yellow-cress
  
• Rorippa sylvestris Creeping Yellow-cress
  
• Rosa arvensis Field Rose
  
• Rosa canina Rose, Dog
  
• Rosa pimpinellifolia Burnet Rose
  
• Rosa rubiginosa Sweet-briar
  
• Rosa sherardii Rose, Sherard's Downy-rose
  
• Rubia peregrina Wild Madder
  
• Rubus caesius Dewberry
  
• Rubus fruticosus Bramble
  
• Rubus idaeus Wild Raspberry
  
• Rubus saxatilis Stone Bramble
  
• Rumex acetosa Common Sorrel
  
• Rumex acetosella Sheep's Sorrel
  
• Rumex conglomeratus Clustered Dock
  
• Rumex crispus Dock, Curled
  
• Rumex hydrolapathum Water Dock
  
• Rumex obtusifolius Broad-leaved Dock
  
• Rumex sanguineus Wood Dock
  
• Ruppia cirrhosa Spiral Tasselweed
  
• Ruppia maritima Beaked Tasselweed
  
• Sagina apetala Annual Pearlwort
  
• Sagina maritima Sea Pearlwort
  
• Sagina nodosa Knotted Pearlwort
  
• Sagina procumbens Pearlwort, Procombent
  
• Sagina subulata Heath Pearlwort
  
• Salicornia europaea Common Glasswort
  
• Salicornia fragilis Yellow Glasswort
  
• Salicornia ramosissima Glasswort, Purple
  
• Salix aurita Eared Willow
  
• Salix caprea Goat Willow
  
• Salix cinerea Grey Willow
  
• Salix purpurea Willow, Purple
  
• Salix repens Creeping Willow
  
• Salix viminalis Osier
  
• Salsola kali Saltwort
  
• Salvia verbenaca Wild Clary
  
• Sambucus ebulus Elder, Dwarf