Saxifraga granulata
Meadow Saxifrage
Saxifraga hypnoides
Mossy Saxifrage
Saxifraga oppositifolia
Purple Saxifrage
Saxifraga rotundifolia
Round-leaved Saxifrage
Saxifraga tridactylites
Rue-leaved Saxifrage
Scabiosa columbaria
Small Scabious
Schaueria calytricha
Golden Plume
Schedonorus giganteus
Giant Fescue
Scheuchzeria palustris
Rannoch-rush
Schismatoglottis calyptrata
Dukaruk
Scindapsus pictus
Satin Pothos
Scleroderma aerolatum
Leopard Earthball
Scrophularia umbrosa
Green Figwort
Scutellaria galericulata
Skullcap
Scutellaria incarnata
Hoary Skullcap
Sedum album
White Stonecrop
Seemannia sylvatica
Bolivian Sunset Gloxinia
Selaginella martensii
Variegated Spikemoss
Selaginella willdenowii
Willdenow's Spikemoss
Selenicereus undatus
Pitahaya
Senecio sarracenicus
Broad-leaved Ragwort
Senecio vernalis
Eastern Groundsel
Senega paniculata
Root Beer Plant
Senna alata
Emperor's Candlesticks
Senna fistula
Golden Shower Tree
Senna obtusifolia
Sicklepod
Sequoiadendron giganteum
Wellingtonia
Seseli libanotis
Moon Carrot
Setaria verticillata
Hooked Bristlegrass
Setaria viridis
Green Bristle-grass
Sicyos edulis
Chayote
Sida acuta
Common Wireweed
Sida rhombifolia
Arrowleaf Sida
Silene conica
Sand Catchfly
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 vulgaris
Bladder Campion
Sisyrinchium bermudiana
Blue-eyed-grass
Solandra grandiflora
Showy Chalicevine
Solanum aethiopicum
Ethiopian Eggplant
Solanum americanum
American Black Nightshade
Solanum chenopodioides
Tall Nightshade
Solanum erianthum
Velvet Nightshade
Solanum melongena
Eggplant
Solanum torvum
Pendejera
Soldanella alpina
Alpine Snowbell
Solidago canadensis
Canadian Goldenrod
Solidago virgaurea
Goldenrod
Sonchus asper
Prickly Sow-thistle
Sorbus aria
Common Whitebeam
Sorbus cambrensis
Welsh Whitebeam
Sorbus leptophylla
Thin-leaved Whitebeam
Sorbus leyana
Ley's Whitebeam
Sorbus minima
Least Whitebeam
Sorbus porrigentiformis
Grey-leaved Whitebeam
Sorbus stenophylla
Llanthony Whitebeam
Sparganium angustifolium
Floating Bur-reed
Spathiphyllum blandum
Pleasant Peace Lily
Spathodea campanulata
African Tulip Tree
Spathoglottis plicata
Philippine Ground Orchid
Spergula arvensis
Corn Spurrey
Spergularia rubra
Sand Spurrey
Spermacoce exilis
False Buttonweed
Spermacoce hispida
Shaggy Buttonweed
Spermacoce remota
Sphagneticola trilobata
Bay Biscayne Creeping-oxeye