- scabrid scabrous
- scandent
- scrub
- season
- seed
- seedling
- self-sterile
- semelauctant
- senescence
- serrate
- sessile
- shear strength
- sheath
- sheath blade
- sheathing organ
- shoot
- silica body
- silica cells
- slenderness ratio
- smoking
- spathe
- specific gravity
- spike
- spikelet
- spine
- spinose
- sporadic
- stamen
- stem
- sterile
- stigma
- straggling
- stress at limit proportionality
- striate
- style
- sub-
- subfamily
- subglobose
- subspecies
- sulphate pulp
- sympodial