Grass Stems - are mostly hollow, cylindrical, and interrupted at intervals by swollen joints or nodes. Stems are rarely branched above the ground and are called CULMS.
Some grasses have stem thatch creep along the surface of the ground and give rise to new shoots (TILLERS) at their nodes. The horizontal stems are called STOLONS. If the horizontal stems go underground, they are called RHIZOMES.
Leaves - originate from the nodes. The lower portion of the leaf forms a sheath, which encloses and protects the young shoots. The second half of the leaf then opens out into the leaf blade.