Samolus valerandi
Brookweed
Saponaria officinalis
Soapwort
Saxifraga cespitosa
Tufted Saxifrage
Saxifraga granulata
Meadow Saxifrage
Saxifraga hypnoides
Mossy Saxifrage
Saxifraga oppositifolia
Purple Saxifrage
Saxifraga spathularis
St Patrick's-cabbage
Saxifraga tridactylites
Rue-leaved Saxifrage
Scleranthus annuus
Annual Knawel
Scorzoneroides autumnalis
Autumn Hawkbit
Scrophularia auriculata
Water Figwort
Scrophularia nodosa
Common Figwort
Scutellaria galericulata
Skullcap
Scutellaria minor
Lesser Skullcap
Senecio inaequidens
Narrow-leaved Ragwort
Senecio viscosus
Sticky Groundsel
Senecio vulgaris
Groundsel
Serratula tinctoria
Saw-wort
Sherardia arvensis
Field Madder
Silene acaulis
Moss Campion
Silene conica
Sand Catchfly
Silene dioica
Red Campion
Silene flos-cuculi
Ragged-Robin
Silene gallica
Small-flowered Catchfly