Rhododendron lindleyi
Rhododendron racemosum
Rhynchospora alba
White Beak-sedge
Ribes rubrum
Red Currant
Ribes sanguineum
Flowering Currant
Riccia fluitans
Floating crystalwort
Riccia nigrella
Black Crystalwort
Riccia subbifurca
Least Crystalwort
Ricinus communis
Castor-oil-plant
Rorippa palustris
Marsh Yellow-cress
Rorippa sylvestris
Creeping Yellow-cress
Rosa arvensis
Field-rose
Rosa caesia
Hairy Dog-rose
Rosa canina
Dog-rose
Rosa canina agg
Dog-rose
Rosa multiflora
Many-flowered Rose
Rosa sherardii
Sherard's Downy-rose
Rosa spinosissima
Burnet Rose
Rosmarinus officinalis
Rosemary
Rubia peregrina
Wild Madder
Rubus caesius
Dewberry
Rubus fruticosus agg.
Blackberry
Rubus idaeus
Raspberry
Rubus nessensis
Rubus saxatilis
Stone Bramble
Rubus scissus
Rubus sp
Rubus spectabilis
Salmonberry
Rubus ulmifolius
Rubus vestitus
Ruella simplex
Mexican Petunia
Ruellia simplex
Mexican Petunia
Ruellia tuberosa
Minnieroot
Rumex acetosa
Common Sorrel
Rumex acetosella
Sheep's Sorrel
Rumex crispus
Curled Dock
Rumex cristatus
Greek Dock
Rumex hydrolapathum
Water Dock
Rumex maritimus
Golden Dock
Rumex obtusifolius
Broad-leaved Dock
Rumex palustris
Marsh Dock
Rumex pulcher
Fiddle Dock
Rumex rupestris
Shore Dock
Rumex scutatus
French Sorrel
Ruppia maritima
Beaked Tasselweed
Ruscus aculeatus
Butcher's-broom
Sabulina verna
Spring Sandwort
Sagina apetala
Annual Pearlwort
Sagina filicaulis
Slender Pearlwort
Sagina nodosa
Knotted Pearlwort
Sagina procumbens
Procumbent Pearlwort
Sagittaria sagittifolia
Arrowhead
Salicornia dolichostachya
Long-spiked Glasswort
Salicornia emerici
Shiny Glasswort
Salicornia europaea
Common Glasswort
Salicornia fragilis
Yellow Glasswort
Salicornia ramosissima
Purple Glasswort
Salix aurita
Eared Willow
Salix caprea
Goat Willow
Salix herbacea
Dwarf Willow
Salix pentandra
Bay Willow
Salix repens
Creeping Willow
Salix x meyeriana
Shiny-leaved Willow
Salsola kali
Prickly Saltwort
Salvia involucrata
Rosy-leaf sage
Salvia officinalis
Sage
Salvia pratensis
Meadow Clary
Salvia verbenaca
Wild Clary
Samanea saman
Raintree
Sambucus canadensis
American Elderberry