Solidago
Solidaster
Sollya
Sonerila
Sophora
Sophrolaeliocattleya
Sorbaria
Sorbus
Sorghastrum
Sparaxis
Sparganium
Spartina
Spartium
Spathiphyllum
Spathodea
Sphaeralcea
Spigelia
Spiraea (spirea)

Sporobolus
Sprekelia
Stachys
Stachyurus
Stangeria
Stanhopea
Stapelia
Stapelianthus
Staphylea
Stauntonia
Stenanthium
Stenocactus
Stenocarpus
Stenocereus
Stenomesson
Stenotus
Stephanandra
Stephanocereus

Stephanotis
Sternbergia
Stigmaphyllon
Stipa
Stokesia
Stomatium
Stratiotes
Strelitzia
Streptocarpus
Streptosolen
Strobilanthes
Stromanthe
Strombocactus
Strongylodon
Stuartia
Stylidium
Stylophorum
Styphelia

Styrax
Succisa
Sulcorebutia
Sutera
Sutherlandia
Swainsona
Swainsonia
Syagrus
Sycopsis
Symphoricarpos
Symphyandra
Symphytum
Symplocos
Synadenium
Syneilesis
Syngonium
Synthyris
Syringa