- sorus
- smoke-tree
- snapdragon
- soap-wort
- soja
- solanaceous
- soya
- soya-bean
- spadices
- spadix
- spearmint
- spermatophyte
- spermologist
- sphagnum
- southernwood
- sow-thistle
- sowbread
- spanish chestnut
- spanker
- spathe
- spatter-dock
- spawn
- speedwell
- spelt
- spermological
- spermatozoid
- spermology
- sphagna
- spicate
- spikelet
- spinage
- spica
- spicated
- spike
- spikenard
- spiky
- spinach
- spinule
- spinulose
- spiraea
- spire
- spleenwort
- sporangia
- sporophyte
- spruce
- spurrey
- spinuleferous
- spinulous
- spirea
- sporangium
- sporiferous
- sporophyll
- stalk
- stamen
- staminate
- standard
- sporophyl
- spur
- spurge
- spurry
- star-apple
- starry-eyed
- squash
- squill
- stamened
- staminaeal
- staminal
- stamineous
- staminiferous
- stelae
- stele
- stem
- stenopetalous
- stenophyllous
- stigmatic
- stimuli
- stipend
- stolon
- stomata
- stone-pine
- stonecrop
- sting
- stipate
- stipellate
- stipule
- stoma
- stigma
- stigmatose
- stimulus
- stipular
- stone
- stone-break
- stoneless
- storax
- stout
- stramonium
- stigmata
- stimulose
- stink-horn
- stipel