Ranunculus sceleratus
Celery-leaved Buttercup
Ranunculus trichophyllus
Thread-leaved Water-crowfoot
Raphanus raphanistrum
Radish
Raphanus sativus
Garden Radish
Reseda lutea
Wild Mignonette
Reseda luteola
Weld
Reynoutria japonica
Japanese Knotweed
Rhamnus cathartica
Buckthorn
Rheum officinale
Tibetan Rhubarb
Rhinanthus alectorolophus
European Yellow-rattle
Rhinanthus angustifolius
Greater Yellow-rattle
Rhinanthus minor
Yellow-rattle
Rhipsalis salicornioides
Spice Cactus
Rhodiola rosea
Roseroot
Rhododendron cinnibarinum
Rhododendron ferrugineum
Alpenrose
Rhododendron lindleyi
Rhododendron loderi
Rhododendron ponticum
Rhododendron
Rhododendron racemosum
Rhododendron (racemosum)
Rhynchospora alba
White Beak-sedge
Rhynchospora fusca
Brown Beak-sedge
Ribes nigrum
Black Currant
Ribes rubrum
Red Currant