Setaria viridis
Green Bristle-grass
Sicyos edulis
Chayote
Sida acuta
Common Wireweed
Sida rhombifolia
Arrowleaf Sida
Silene conica
Sand Catchfly
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 chenopodioides
Tall Nightshade
Solanum erianthum
Velvet Nightshade
Solanum melongena
Eggplant
Soldanella alpina
Alpine Snowbell
Solidago canadensis
Canadian Goldenrod
Solidago virgaurea
Goldenrod
Sonchus asper
Prickly Sow-thistle
Sorbus aria
Common Whitebeam
Sorbus minima
Least Whitebeam
Sparganium angustifolium
Floating Bur-reed
Spathiphyllum blandum
Pleasant Peace Lily