Spergularia rubra
Sand Spurrey
Spergularia rupicola
Rock Sea-spurrey
Spiraea x rosalba
Intermediate Bridewort
Spiranthes romanzoffiana
Irish Lady's-tresses
Spiranthes spiralis
Autumn Lady's-tresses
Spirodela polyrhiza
Greater Duckweed
Stachys arvensis
Field Woundwort
Stachys germanica
Downy Woundwort
Stachys sylvatica
Hedge Woundwort
Stellaria alsine
Bog Stitchwort
Stellaria aquatica
Water Chickweed
Stellaria holostea
Greater Stitchwort
Stellaria palustris
Marsh Stitchwort
Streptocarpus saxorum
False African Violet
Stuckenia pectinata
Fennel Pondweed
Succisa pratensis
Devil's-bit Scabious
Swietenia macrophylla
Mahogany
Symphyotrichum lanceolatum
Narrow-leaved Michaelmas-daisy
Symphytum officinale
Common Comfrey
Symphytum orientale
White Comfrey
Symphytum x hidcotense
Hidcote Comfrey
Symphytum x uplandicum
Russian Comfrey
Syntrichia ruralis
Sand-hill Screw-moss
Tamus communis
Black Bryony
Tanacetum vulgare
Tansy
Taraxacum agg.
Dandelion
Taraxacum britannicum
Taraxacum falcatum
Dandelion
Taraxacum palustre
Taraxacum Section Ruderalia
Dandelion
Taxus baccata
Yew
Teesdalia nudicaulis
Shepherd's Cress
Tellima grandiflora
Fringecups
Tephroseris integrifolia
South Stack Fleawort
Thalictrum flavum
Common Meadow-rue
Thalictrum minus
Lesser Meadow-rue
Thelypteris palustris
Marsh Fern
Thymus drucei
Wild Thyme
Tilia cordata
Small-leaved Lime
Tilia sp.
Lime
Tofieldia pusilla
Scottish Asphodel
Torilis japonica
Upright Hedge-parsley
Trichomanes speciosum
Killarney Fern
Trichophorum germanicum
Deergrass
Trifolium campestre
Hop Trefoil
Trifolium dubium
Lesser Trefoil
Trifolium medium
Zigzag Clover
Trifolium micranthum
Slender Trefoil
Trifolium scabrum
Rough Clover
Triglochin maritima
Sea Arrowgrass
Triglochin palustris
Marsh Arrowgrass
Trinia glauca
Honewort
Tripleurospermum inodorum
Scentless Mayweed
Tripleurospermum maritimum
Sea Mayweed
Tripolium pannonicum
Sea Aster
Tristagma uniflorum
Spring Starflower
Trocdaris verticillata
Whorled Caraway
Trollius europaeus
Globeflower
Tuberaria guttata
Spotted Rock-rose
Tussilago farfara
Colt's-foot
Typha angustifolia
Lesser Bulrush
Typha latifolia
Bulrush
Ulex europaeus
Gorse
Ulex gallii
Western Gorse
Ulmus glabra
Wych Elm
Ulmus minor
Small-leaved Elm
Umbilicus rupestris
Navelwort
Urtica dioica
Common Nettle
Usnea fragilescens
Utricularia minor
Lesser Bladderwort