Salicornia europaea
Common Glasswort
Salicornia fragilis
Yellow Glasswort
Salicornia ramosissima
Purple Glasswort
Salix aurita
Eared Willow
Salix caprea
Goat Willow
Salix cinerea
Grey Willow
Salix herbacea
Dwarf Willow
Salix pentandra
Bay Willow
Salix purpurea
Purple Willow
Salix repens
Creeping Willow
Salix viminalis
Osier
Salsola kali
Prickly Saltwort
Salvia verbenaca
Wild Clary
Sambucus nigra
Elder
Samolus valerandi
Brookweed
Sanguisorba officinalis
Great Burnet
Sanicula europaea
Sanicle
Saxifraga aizoides
Yellow Saxifrage
Saxifraga cernua
Drooping Saxifrage
Saxifraga cespitosa
Tufted Saxifrage
Saxifraga granulata
Meadow Saxifrage
Saxifraga hirsuta
Kidney Saxifrage
Saxifraga hypnoides
Mossy Saxifrage
Saxifraga oppositifolia
Purple Saxifrage
Saxifraga rosacea
Irish Saxifrage
Saxifraga spathularis
St Patrick's-cabbage
Saxifraga tridactylites
Rue-leaved Saxifrage
Scabiosa columbaria
Small Scabious
Schedonorus giganteus
Giant Fescue
Scheuchzeria palustris
Rannoch-rush
Schoenoplectus lacustris
Common Club-rush
Schoenus nigricans
Black Bog-rush
Scilla autumnalis
Autumn Squill
Scilla verna
Spring Squill
Scirpoides holoschoenus
Round-headed Club-rush
Scirpus sylvaticus
Wood Club-rush
Scleranthus annuus
Annual Knawel
Scleranthus perennis
Perennial Knawel
Scorzoneroides autumnalis
Autumn Hawkbit
Scrophularia auriculata
Water Figwort
Scrophularia nodosa
Common Figwort
Scrophularia umbrosa
Green Figwort
Scutellaria galericulata
Skullcap
Scutellaria minor
Lesser Skullcap
Sedum acre
Biting Stonecrop
Sedum anglicum
English Stonecrop
Selaginella selaginoides
Lesser Clubmoss
Senecio sylvaticus
Heath Groundsel
Senecio vulgaris
Groundsel
Serratula tinctoria
Saw-wort
Seseli libanotis
Moon Carrot
Sherardia arvensis
Field Madder
Sibthorpia europaea
Cornish Moneywort
Silaum silaus
Pepper-saxifrage
Silene acaulis
Moss Campion
Silene conica
Sand Catchfly
Silene dioica
Red Campion
Silene flos-cuculi
Ragged-Robin
Silene latifolia
White Campion
Silene nutans
Nottingham Catchfly
Silene uniflora
Sea Campion
Silene viscaria
Sticky Catchfly
Silene vulgaris
Bladder Campion
Sison amomum
Stone Parsley
Sisyrinchium bermudiana
Blue-eyed-grass
Solanum dulcamara
Bittersweet
Solidago virgaurea
Goldenrod
Sonchus arvensis
Perennial Sow-thistle
Sonchus asper
Prickly Sow-thistle
Sonchus oleraceus
Smooth Sow-thistle