Stachys albens Stachys albotomentosa
Stachys byzantina Stachys byzantina 'Big Ears'
Stachys byzantina 'Helen von Stein' Stachys byzantina 'Silver Carpet'
Stachys macrantha 'Robusta' Stachys monnieri 'Hummelo'
Stachys officinalis Stachys officinalis 'Grandiflora'
Stachys palustris Stapelia
Stapelia gigantea Stapelia grandiflora
Stapelia schinzii Stellaria media
Stenocereus alamosensis Stenocereus dumortieri
Stenocereus eruca Stenocereus griseus
Stenocereus gummosus Stenocereus hystrix
Stenocereus montanus Stenocereus thurberi
Stenospermation x 'San Carlos' Stenotaphrum secundatum 'Variegatum'
Sternbergia clusiana Sternbergia lutea
Stevia rebaudiana Stevia spp.
Stictocardia beraviensis Stipa arundinacea
Stipa gigantea Stipa tenuissima
Stokesia laevis Stokesia laevis 'Blue Danube'
Stokesia laevis 'Honeysong Purple' Stokesia laevis 'Klaus Jelitto'
Stokesia laevis 'Mary Gregory' Stokesia laevis 'Omega Skyrocket'
Stokesia laevis 'Purple Parasols' Stokesia laevis 'Silver Moon'
Stratiotes aloides Strelitzia reginae
Streptocarpus x hybridus Streptocarpus saxorum
Strobilanthes dyerianus Stromanthe 'Burle Marx'
Stylophorum diphyllum Sutera cordata 'Abunda White Improved'
Sutera cordata 'Giant Snowflake' Sutera diffusa 'Sunlovers Bacopa 1766'
Swainsona formosa Symphyotrichum carolinianum
Symphyotrichum cordifolium 'Ideal' Symphyotrichum dumosum 'Bonny Blue'
Symphyotrichum dumosum 'Kiestrbl (Sapphire)' Symphyotrichum dumosum 'Lady in Blue'
Symphyotrichum dumosum 'Persian Rose' Symphyotrichum dumosum 'Peter Harrison'
Symphyotrichum dumosum 'Rose Serenade' Symphyotrichum dumosum 'Snow Cushion'
Symphyotrichum dumosum 'Snow Flurry' Symphyotrichum dumosum 'Winston Churchill'
Symphyotrichum dumosum 'Wood's Light Blue' Symphyotrichum dumosum 'Wood's Pink'
Symphyotrichum dumosum 'Wood's Purple' Symphyotrichum georgianum
Symphyotrichum laeve 'Bluebird' Symphyotrichum lateriflorum 'Lady in Black'
Symphyotrichum lateriflorum 'Prince' Symphyotrichum novae-angliae
Symphyotrichum novae-angliae 'Alert' Symphyotrichum novae-angliae 'Alma Potschke'
Symphyotrichum novae-angliae 'Bressingham Pink' Symphyotrichum novae-angliae 'Hella Lacy'
Symphyotrichum novae-angliae 'Purple Dome' Symphyotrichum novae-angliae 'Red Star'
Symphyotrichum novae-angliae 'Treasurer' Symphyotrichum novi-belgii
Symphyotrichum novi-belgii 'Frolic' Symphyotrichum novi-belgii 'Henry III'
Symphyotrichum novi-belgii 'Marie III' Symphyotrichum novi-belgii 'Patricia Ballard'
Symphyotrichum novi-belgii 'Peter III' Symphyotrichum novi-belgii 'Prof. Anton Kippenberg'
Symphyotrichum novi-belgii 'Shout' Symphyotrichum novi-belgii 'Snowball'
Symphyotrichum novi-belgii 'Twist' Symphyotrichum pilosum
Symphytum caucasicum Symphytum grandiflorum
Symphytum grandiflorum 'Goldsmith' Symphytum grandiflorum 'Hidcote Blue'
Symphytum officinale Symphytum x uplandicum 'Axminster Gold'
Symphytum x uplandicum 'Variegatum' Symplocarpus foetidus
Syneilesis aconitifolia Syngonium podophyllum 'White Butterfly'