Sparganium emersum - Stellaria calycantha
- Sparganium emersum
- Sparganium erectum
- Sparganium erectum ssp. stoloniferum
- Sparganium eurycarpum
- Sparganium fluctuans
- Sparganium glomeratum
- Sparganium hyperboreum
- Sparganium natans
- Spartina
- Spartina alterniflora
- Spartina anglica
- Spartina bakeri
- Spartina caespitosa
- Spartina cynosuroides
- Spartina densiflora
- Spartina foliosa
- Spartina gracilis
- Spartina maritima
- Spartina patens
- Spartina pectinata
- Spartina spartinae
- Spartina townsendii
- Spartium
- Spartium junceum
- Spathodea
- Spathodea campanulata
- Spathoglottis
- Spathoglottis carolinensis
- Spathoglottis elmeri
- Spathoglottis micronesiaca
- Spathoglottis plicata
- Speerschneidera
- Speerschneidera euploca
- Spergula
- Spergula arvensis
- Spergula morisonii
- Spergula pentandra
- Spergularia
- Spergularia atrosperma
- Spergularia bocconii
