Vascular Cambium: Wood formation in plants is facilitated by the vascular cambium, a lateral meristematic tissue found in dicotyledons (dicots) and gymnosperms. The vascular cambium is responsible for secondary growth, which leads to an increase in stem thickness through the production of secondary xylem (wood) and secondary phloem.

Monocots Lack Vascular Cambium: Monocots generally lack a vascular cambium. Instead, their vascular bundles are scattered throughout the stem and do not form a continuous ring like in dicots. Without a vascular cambium, monocots cannot produce secondary xylem or phloem, which are essential for wood formation.

Vascular Bundle Arrangement: In monocots, vascular bundles are scattered throughout the stem's ground tissue. Each vascular bundle contains xylem and phloem, but they are not arranged in a way that allows for secondary growth. This scattered arrangement is in contrast to the organized ring of vascular bundles in dicots, which facilitates the development of the vascular cambium.

Alternative Support Systems: Instead of wood, monocots rely on other structural adaptations for support. For example, some monocots, like palm trees, have a "pseudo-wood" formed by the accumulation of fibrous vascular bundles and strengthening tissues. Others, like grasses, depend on turgor pressure (water pressure within cells) and fibrous tissues for support.