- Sabal
- Saccharum
- Sadleria
- Safflower
- Sage
- Sagebrush
- Sagina
- Sagittaria
- Sago Palm
- Saguaro
- Saintpaulia
- Salix
- Salpiglossus
- Salvia
- Salvinia
- Sambucus
- Sanchezia
- Sand Verbena
- Sandersonia
- Sandwort
- Sanguinaria
- Sanguisorba
- Sansevieria
- Santolina
- Sanvitalia
- Sapindus
- Sapium
- Saponaria
- Sarcocapnos
- Sarcocaulon
- Sarcococca
- Saritaea
- Sarmienta
- Sarracenia
- Sasa
- Sassafras
- Satureja
- Sauromatum
- Sausage Tree
- Savory
- Saw Palm
- Saxegothaea
- Saxifraga
- Saxifrage
- Scabiosa
- Scabious Plant
- Scadoxus
- Scaevola
- Scent Myrtle
- Schefflera
- Schima
- Schinus
- Schisandra
- Schizachyrium
- Schizanthus
- Schizopetalon
- Schizophragma
- Schizostylis
- Schlumbergera
- Schoenoplectus
- Schomburgkia
- Schotia
- Schwantesia
- Sciadopitys
- Scilla
- Scindapsus
- Scirpoides
- Sclerocactus
- Scoliopsus
- Scopolia
- Scorpion Orchid
- Screw Pine
- Scrophularia
- Scutellaria
- Sea Grape
- Sea Holly
- Sea Lavender
- Sea Lily
- Securinega
- Sedge
- Sedum
- Selaginella
- Selago
- Selenicereus
- Self-heal
- Selinum
- Semele
- Semiaquilegia
- Semiarundinaria
- Sempervivum
- Seneca
- Senecio
- Senna
- Sentry Palm
- Sequoia
- Sequoiadendron
- Seriphidium
- Serissa
- Serruria
- Sesbania