Samolus parviflorus Sanguinaria canadensis
Sanguinaria canadensis 'Multiplex' Sanguisorba minor
Sanguisorba obtusa Sanguisorba obtusa 'Lemon Splash'
Sansevieria grandis Sansevieria trifasciata
Sansevieria trifasciata 'Laurentii' Sansevieria trifasciata 'Moonshine'
Sansevieria zeylanica Santolina chamaecyparissus
Santolina chamaecyparissus 'Lavender Cotton' Santolina chamaecyparissus 'Lemon Queen'
Santolina chamaecyparissus 'Nana' Santolina chamaecyparissus var. insalaris
Santolina pinnata 'Edward Bowles' Santolina rosmarinifolia
Sanvitalia procumbens 'Aztec Gold' Saponaria x lempergii 'Max Frei'
Saponaria ocymoides Saponaria officinalis
Sarcodes sanguinea Sarracenia
Sarracenia 'Case's Resolve' Sarracenia x catesbaei
Sarracenia flava Sarracenia flava 'Peaches & Green'
Sarracenia flava var. rubricorpora Sarracenia leucophylla
Sarracenia purpurea Sarracenia x wrigleyana 'Scarlet Belle'
Sasa palmata f. nebulosa Sasa spp.
Sasa veitchii Sasa veitchii ssp. nana
Sasaella ramosa Satureja montana
Sauromatum venosum Saururus cernuus
Saururus chinensis Saxifraga 'Apple Blossom'
Saxifraga 'Peter Pan' Saxifraga 'Variegata'
Saxifraga x arendsii 'Purple Robe' Saxifraga x arendsii 'Triumph'
Saxifraga davurica Saxifraga fortunei 'Velvet'
Saxifraga paniculata Saxifraga x salmonica
Saxifraga stolonifera Saxifraga stolonifera 'Harvest Moon'
Saxifraga stolonifera 'Maroon Beauty' Saxifraga trifurcata
Saxifraga x urbium Saxifraga x urbium 'London Pride'
Scabiosa caucasica 'Fama' Scabiosa caucasica 'Perfecta Alba'
Scabiosa columbaria 'Butterfly Blue' Scabiosa columbaria 'Pink Mist'
Scadoxus 'King Albert' Scadoxus multiflorus
Scaevola x 'Blue Shamrock' Scaevola x 'Fancy'
Scaevola 'Mauve Clusters' Scaevola aemula
Scaevola aemula 'Newon (New WonderŽ)' Schizachyrium scoparium
Schizachyrium scoparium 'The Blues' Schlumbergera x buckleyi
Schlumbergera truncata Schoenoplectus lacustris 'Albescens'
Schoenoplectus lacustris ssp. tabernaemontani 'Zebrinus' Schoenus pauciflorus
Scilla bifolia Scilla peruviana
Scilla siberica Scutellaria costaricana
Scutellaria suffrutescens Scutellaria wrightii
Securigera varia