Saxifraga spathularis
St Patrick's-cabbage
Saxifraga tridactylites
Rue-leaved Saxifrage
Saxifraga umbrosa
Pyrenean Saxifrage
Saxifraga x polita
False Londonpride
Scabiosa columbaria
Small Scabious
Schaueria calytricha
Golden Plume
Schedonorus giganteus
Giant Fescue
Scheuchzeria palustris
Rannoch-rush
Schismatoglottis calyptrata
Dukaruk
Schizostylis coccinea
Kaffir Lily
Schlumbergera bridgesii
Christmas cactus
Schoenoplectus lacustris
Common Club-rush
Schoenoplectus tabernaemontani
Grey Club-rush
Schoenus nigricans
Black Bog-rush
Scilla autumnalis
Autumn Squill
Scilla bifolia
Alpine Squill
Scilla forbesii
Glory-of-the-snow
Scilla liliohyacinthus
Pyrenean Squill
Scilla luciliae
Boissier's Glory-of-the-snow
Scilla peruviana
Portuguese Squill
Scilla siberica
Siberian Squill
Scilla verna
Spring Squill
Scindapsus pictus
Satin Pothos
Scirpoides holoschoenus
Round-headed Club-rush
Scirpus sylvaticus
Wood Club-rush
Scleranthus annuus
Annual Knawel
Scleranthus perennis
Perennial Knawel
Scorzoneroides autumnalis
Autumn Hawkbit
Scrophularia auriculata
Water Figwort
Scrophularia nodosa
Common Figwort
Scrophularia umbrosa
Green Figwort
Scutellaria galericulata
Skullcap
Scutellaria incarnata
Hoary Skullcap
Scutellaria minor
Lesser Skullcap
Scyphiphora hydrophylacea
Nilad
Secale cereale
Rye
Sedum acre
Biting Stonecrop
Sedum album
White Stonecrop
Sedum anglicum
English Stonecrop
Sedum sexangulare
Tasteless Stonecrop
Seemannia sylvatica
Bolivian Sunset Gloxinia
Selaginella martensii
Variegated Spikemoss
Selaginella selaginoides
Lesser Clubmoss
Selaginella willdenowii
Willdenow's Spikemoss
Selenicereus undatus
Pitahaya
Sempervivum arachnoideum
Cobweb House-leek
Senecio cambrensis
Welsh Groundsel
Senecio inaequidens
Narrow-leaved Ragwort
Senecio sarracenicus
Broad-leaved Ragwort
Senecio squalidus
Oxford Ragwort
Senecio sylvaticus
Heath Groundsel
Senecio vernalis
Eastern Groundsel
Senecio viscosus
Sticky Groundsel
Senecio vulgaris
Groundsel
Senega paniculata
Root Beer Plant
Senna alata
Emperor's Candlesticks
Senna fistula
Golden Shower Tree
Senna obtusifolia
Sicklepod
Senna surattensis
Scrambled Egg Tree
Sequoia sempervirens
Coastal Redwood
Sequoiadendron giganteum
Wellingtonia
Serratula tinctoria
Saw-wort
Seseli libanotis
Moon Carrot
Sesuvium portulacastrum
Sea Purslane
Setaria palmifolia
Palm Grass
Setaria verticillata
Hooked Bristlegrass
Setaria viridis
Green Bristle-grass
Sherardia arvensis
Field Madder
Sibthorpia europaea
Cornish Moneywort
Sicyos edulis
Chayote