n.
Plant axis that emerges from the roots, supports the branches, bears buds and shoots with leaves, and contains the vascular (conducting) tissues ( xylem and phloem ) that transport water, minerals, and food to other parts of the plant.
The pith (a central core of spongy tissue) is surrounded by strands (in dicots; see cotyledon ) or bundles (in monocots) of conducting xylem and phloem, then by the cortex and outermost epidermis, or bark . The cambium (an area of actively dividing cells) lies just below the bark. Lateral buds and leaves grow out of the stem at intervals called nodes; the intervals on the stem between the nodes are called internodes. In flowering plants, various stem modifications ( rhizome , corm , tuber , bulb , stolon ) let the plant survive dormantly for years, store food, or sprout asexually. All green stems perform photosynthesis , as do leaves; in plants such as the cacti (see cactus ) and asparagus , the stem is the chief site of photosynthesis.