Saxifraga x polita
False Londonpride
Scilla bifolia
Alpine Squill
Scilla liliohyacinthus
Pyrenean Squill
Scilla peruviana
Portuguese Squill
Scilla siberica
Siberian Squill
Sedum sexangulare
Tasteless Stonecrop
Sempervivum arachnoideum
Cobweb House-leek
Senecio inaequidens
Narrow-leaved Ragwort
Senecio sarracenicus
Broad-leaved Ragwort
Senecio squalidus
Oxford Ragwort
Senecio vernalis
Eastern Groundsel
Senecio viscosus
Sticky Groundsel
Sequoia sempervirens
Coastal Redwood
Sequoiadendron giganteum
Wellingtonia
Setaria viridis
Green Bristle-grass
Silene armeria
Sweet-William Catchfly
Silene chalcedonica
Maltese-Cross
Sisyrinchium montanum
American Blue-eyed-grass
Smyrnium perfoliatum
Perfoliate Alexanders
Solanum chenopodioides
Tall Nightshade
Solanum nitidibaccatum
Green Nightshade
Soleirolia soleirolii
Mind-your-own-business
Solidago canadensis
Canadian Goldenrod
Solidago gigantea
Early Goldenrod