- sagittate
- sap
- scale
- sclereid
- sclerenchyma
- secondary thickening
- seed
- seed plants
- self-pollination
- sepal
- sepaloid
- septum
- serrate
- sessile
- sheath
- shoot
- shrub
- simple
- spadix
- spathe
- spatulate
- spicate
- spike
- spikelet
- spur
- stamen
- staminate
- staminode
- starch
- stellate
- stem
- sterile
- stigma
- stipulate
- stipule
- stolon
- stone cells
- striate
- style
- succulent
- sucker
- superior
- syncarp