Poa annua
Annual Meadow-grass
Poa compressa
Flattened Meadow-grass
Poa humilis
Spreading Meadow-grass
Poa trivialis
Rough Meadow-grass
Polygonatum multiflorum
Solomon's-seal
Polygonatum odoratum
Angular Solomon's-seal
Polygonatum verticillatum
Whorled Solomon's-seal
Polygonatum x hybridum
Garden Solomon's-seal
Polypogon viridis
Water Bent
Pontederia crassipes
Water Hyacinth
Potamogeton coloratus
Fen Pondweed
Potamogeton crispus
Curled Pondweed
Potamogeton lucens
Shining Pondweed
Potamogeton natans
Broad-leaved Pondweed
Potamogeton polygonifolius
Bog Pondweed
Pseudorchis albida
Small-white Orchid
Ravenala madagascariensis
East-West Palm
Rhynchospora alba
White Beak-sedge
Rhynchospora fusca
Brown Beak-sedge
Romulea columnae
Sand Crocus
Ruppia maritima
Beaked Tasselweed
Ruscus aculeatus
Butcher's-broom
Sagittaria sagittifolia
Arrowhead
Schedonorus giganteus
Giant Fescue
Scheuchzeria palustris
Rannoch-rush
Schismatoglottis calyptrata
Dukaruk
Schizostylis coccinea
Kaffir Lily
Schoenoplectus lacustris
Common Club-rush
Schoenoplectus tabernaemontani
Grey Club-rush
Schoenus nigricans
Black Bog-rush
Scilla autumnalis
Autumn Squill
Scilla bifolia
Alpine Squill
Scilla forbesii
Glory-of-the-snow
Scilla liliohyacinthus
Pyrenean Squill
Scilla luciliae
Boissier's Glory-of-the-snow
Scilla peruviana
Portuguese Squill
Scilla siberica
Siberian Squill
Scilla verna
Spring Squill
Scindapsus pictus
Satin Pothos
Scirpoides holoschoenus
Round-headed Club-rush
Scirpus sylvaticus
Wood Club-rush
Secale cereale
Rye
Setaria verticillata
Hooked Bristlegrass
Setaria viridis
Green Bristle-grass
Simethis mattiazzii
Kerry Lily
Sisyrinchium bermudiana
Blue-eyed-grass
Sisyrinchium montanum
American Blue-eyed-grass
Sparganium angustifolium
Floating Bur-reed
Sparganium erectum
Branched Bur-reed
Sparganium natans
Least Bur-reed
Spartina anglica
Common Cord-grass
Spathiphyllum blandum
Pleasant Peace Lily
Spathoglottis plicata
Philippine Ground Orchid
Spiranthes romanzoffiana
Irish Lady's-tresses
Spiranthes spiralis
Autumn Lady's-tresses
Spirodela polyrhiza
Greater Duckweed
Sternbergia lutea
Winter Daffodil
Stromanthe thalia
Stuckenia pectinata
Fennel Pondweed
Syngonium auritum
Arrowhead Vine
Tamus communis
Black Bryony
Thysanolaena latifolia
Tiger Grass
Tofieldia pusilla
Scottish Asphodel
Trachycarpus fortunei
Chusan Palm
Tradescantia pallida
Purple Heart
Tradescantia spathacea
Oyster Plant
Trichophorum germanicum
Deergrass
Triglochin maritima
Sea Arrowgrass
Triglochin palustris
Marsh Arrowgrass
Trimezia coerulea
Walking Iris