Rabbit-tobacco
Rabbitfoot Clover
Racemed Milkwort
Radish
Ragged Robin
Ragweed
Ragwort
Rambling Dewberry
Ramp
Rampion Bellflower
Ramtilla
Rannoch-rush
Rape
Rare Clubmoss
Rattlebox
Rattlesnake Brome
Rattlesnake Fern
Rattlesnake Mannagrass
Rattlesnake Plantain
Rattlesnakeroot
Rattlesnakeweed
Ravenfoot Sedge
Ravennagrass
Rayless Alkali Aster
Recurved Blackberry
Red Amaranth
Red Baneberry
Red Catchfly
Red Clover
Red Columbine
Red Currant
Red Elderberry
Red Fescue
Red Haw
Red Hempnettle
Red Hickory
Red Maple
Red Mulberry
Red Sandspurry
Red Trillium
Redbud
Redosier Dogwood
Redring Milkweed
Redroot Amaranth