Sparganium natans
Least Bur-reed
Sparmannia sp.
African Hemp
Spartina anglica
Common Cord-grass
Spathiphyllum blandum
Pleasant Peace Lily
Spathodea campanulata
African Tulip Tree
Spathoglottis plicata
Philippine Ground Orchid
Spergula arvensis
Corn Spurrey
Spergularia marina
Lesser Sea-spurrey
Spergularia media
Greater Sea-spurrey
Spergularia rubra
Sand Spurrey
Spergularia rupicola
Rock Sea-spurrey
Spermacoce exilis
False Buttonweed
Spermacoce hispida
Shaggy Buttonweed
Spermacoce remota
Sphagneticola trilobata
Bay Biscayne Creeping-oxeye
Sphagnum denticulatum
Cow-horn Bog-moss
Spigelia anthelmia
West Indian Pinkroot
Spiraea canescens
Himalayan Spiraea
Spiraea x rosalba
Intermediate Bridewort
Spiranthes romanzoffiana
Irish Lady's-tresses
Spiranthes spiralis
Autumn Lady's-tresses
Spirodela polyrhiza
Greater Duckweed
Splachnum ampullaceum
Cruet Collar-moss
Stachys alpina
Limestone Woundwort
Stachys arvensis
Field Woundwort
Stachys byzantina
Lamb's-ear
Stachys germanica
Downy Woundwort
Stachys palustris
Marsh Woundwort
Stachys sylvatica
Hedge Woundwort
Stachytarpheta jamaicensis
Blue Porterweed
Stapelia variegata
Staphylea pinnata
Bladdernut
Stellaria alsine
Bog Stitchwort
Stellaria aquatica
Water Chickweed
Stellaria graminea
Lesser Stitchwort
Stellaria holostea
Greater Stitchwort
Stellaria media
Common Chickweed
Stellaria neglecta
Greater Chickweed
Stellaria palustris
Marsh Stitchwort
Sternbergia lutea
Winter Daffodil
Streptocarpus saxorum
False African Violet
Strobilanthes alternata
Red-ivy
Strobilanthes reptans
Waffle Plant
Stromanthe thalia
Stuckenia pectinata
Fennel Pondweed
Stylosanthes guianensis
Stylo
Suaeda maritima
Annual Sea-blite
Succisa pratensis
Devil's-bit Scabious
Swietenia macrophylla
Mahogany
Swietenia macrphylla
Honduran Mahogany
Symphoricarpos albus
Snowberry
Symphyotrichum lanceolatum
Narrow-leaved Michaelmas-daisy
Symphytum asperum
Rough Comfrey
Symphytum officinale
Common Comfrey
Symphytum orientale
White Comfrey
Symphytum x hidcotense
Hidcote Comfrey
Symphytum x uplandicum
Russian Comfrey
Synedrella nodiflora
Nodeweed
Syngonium auritum
Arrowhead Vine
Syntrichia ruralis
Sand-hill Screw-moss
Syzygium samarangense
Wax Apple
Tabernaemontana alternifolia
East Indian Rosebay
Tabernaemontana divaricata
Carnation of India
Tacinga inamoena
Quipá
Tagetes lucida
Mexican Tarragon
Talinum paniculatum
Fameflower
Tamarix gallica
Tamarisk
Tamus communis
Black Bryony
Tanacetum parthenium
Feverfew
Tanacetum vulgare
Tansy