Shoot system

The shoot system develops from the plumule of the germinating seed's embryo: the epicotyl elongates to form the stem axis, whose actively dividing apical meristem at the tip produces a mass of tissue called the leaf primordium at intervals along the way. The point on the stem from which a leaf arises is a node, and the stretch of stem between two successive nodes is an internode.

The stem is characteristically the aerial part of the plant, growing upward toward light and away from gravity (positively phototropic, negatively geotropic), and unlike the root it bears nodes and internodes. It carries vegetative buds for further growth and floral buds for reproduction, and normally ends in a terminal bud; the young stem is green and photosynthetic, its branches arise exogenously, and some stems bear multicellular hairs. …