Saxifraga spathularis
St Patrick's-cabbage
Saxifraga tridactylites
Rue-leaved Saxifrage
Saxifraga x polita
False Londonpride
Scabiosa columbaria
Small Scabious
Schoenoplectus tabernaemontani
Grey Club-rush
Scilla verna
Spring Squill
Scirpus sylvaticus
Wood Club-rush
Scrophularia auriculata
Water Figwort
Scrophularia nodosa
Common Figwort
Scrophularia umbrosa
Green Figwort
Scutellaria galericulata
Skullcap
Scutellaria minor
Lesser Skullcap
Senecio cambrensis
Welsh Groundsel
Senecio inaequidens
Narrow-leaved Ragwort
Senecio vulgaris
Groundsel
Sequoia sempervirens
Coastal Redwood
Serratula tinctoria
Saw-wort
Sherardia arvensis
Field Madder
Sibthorpia europaea
Cornish Moneywort
Silene conica
Sand Catchfly
Silene dioica
Red Campion
Silene flos-cuculi
Ragged-Robin
Silene latifolia
White Campion
Silene noctiflora
Night-flowering Catchfly