Saxifraga granulata
Meadow Saxifrage
Saxifraga hypnoides
Mossy Saxifrage
Saxifraga oppositifolia
Purple Saxifrage
Saxifraga paniculata
Livelong Saxifrage
Saxifraga rosacea
Irish Saxifrage
Saxifraga rotundifolia
Round-leaved Saxifrage
Saxifraga spathularis
St Patrick's-cabbage
Saxifraga tridactylites
Rue-leaved Saxifrage
Saxifraga umbrosa
Pyrenean Saxifrage
Scabiosa columbaria
Small Scabious
Schaueria calytricha
Golden Plume
Schizostylis coccinea
Kaffir Lily
Schlumbergera bridgesii
Christmas cactus
Schoenoplectus tabernaemontani
Grey Club-rush
Scilla autumnalis
Autumn Squill
Scilla bifolia
Alpine Squill
Scilla forbesii
Glory-of-the-snow
Scilla luciliae
Boissier's Glory-of-the-snow
Scilla peruviana
Portuguese Squill
Scilla siberica
Siberian Squill
Scilla verna
Spring Squill
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
Sedum acre
Biting Stonecrop
Sedum album
White Stonecrop
Sedum anglicum
English Stonecrop
Sedum sexangulare
Tasteless Stonecrop
Seemannia sylvatica
Bolivian Sunset Gloxinia
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 fistula
Golden Shower Tree
Senna obtusifolia
Sicklepod
Serratula tinctoria
Saw-wort
Seseli libanotis
Moon Carrot
Sherardia arvensis
Field Madder
Sibthorpia europaea
Cornish Moneywort
Sicyos edulis
Chayote
Sida rhombifolia
Arrowleaf Sida
Silaum silaus
Pepper-saxifrage
Silene acaulis
Moss Campion
Silene armeria
Sweet-William Catchfly
Silene chalcedonica
Maltese-Cross
Silene conica
Sand Catchfly
Silene dioica
Red Campion
Silene flos-cuculi
Ragged-Robin
Silene gallica
Small-flowered Catchfly
Silene latifolia
White Campion
Silene noctiflora
Night-flowering Catchfly
Silene nutans
Nottingham Catchfly
Silene uniflora
Sea Campion
Silene viscaria
Sticky Catchfly
Silene vulgaris
Bladder Campion
Silybum marianum
Milk Thistle
Simethis mattiazzii
Kerry Lily