Radermachera yunnanensis
Raphanus raphanistrum
Wild Radish
Ricinus communis
Castor-oil-plant
Rivini humilis
Bloodberry
Rubus fraxinifolius
Mountain Raspberry
Ruella simplex
Mexican Petunia
Ruellia simplex
Mexican Petunia
Ruellia tuberosa
Minnieroot
Salvia involucrata
Rosy-leaf sage
Salvia leucanthe
Mexican Bush Sage
Salvia splendens
Bonfire Salvia
Samanea saman
Raintree
Sambucus canadensis
American Elderberry
Sandoricum koetjape
Santol
Schaueria calytricha
Golden Plume
Seemannia sylvatica
Bolivian Sunset
Selaginella martensii
Variegated Spikemoss
Selaginella willdenowii
Willdenow's Spikemoss
Senna obtusifolia
Sicklepod
Sicyos edulis
Chayote
Sida acuta
Common Wireweed
Sida rhombifolia
Arrowleaf Sida
Solandra grandiflora
Showy Chalicevine
Solanum erianthum
Velvet Nightshade