- saccate
- sagittate
- sagittiform
- saponin
- saprophyte
- sapwood
- scabrid
- scalariform
- scandent
- scarification
- scarious
- scimitar-like
- scrub
- scurfy
- section
- sedative
- seed
- seedling
- self-pollination
- semi-
- senescence
- sepal
- sept
- septate
- septum
- seriate
- sericeous
- serrate
- serrulate
- sessile
- seta
- setaceous
- setiform
- setose
- setulose
- shrub
- sigmoid
- siliceous
- silique
- simple
- sinuate
- sinus
- slender
- softwood
- solfatares
- spathaceous
- spathulate
- speciation
- spherical
- spicule
- spike
- spikelet
- spine
- spinescent
- spiral
- spur
- spurred
- stalk
- stamen
- staminal
- staminode
- standard
- stellate hairs
- stem
- sterile
- stigma
- stilt roots
- stipe
- stipel
- stipitate
- stipular gland
- stipular spines
- stipulate
- stipule
- stout
- striate
- strigose
- style
- sub-
- subsessile
- subspecies
- subulate
- subverticillate
- suckers
- sulcate
- superior
- suture
- sympatric
- sympetalous
- synonym