Anatomy Of Flowering Plants - Vascular Bundles

Internal stem structure differs between monocots and dicots, and NCERT highlights vascular bundle arrangement as a key diagnostic feature. In a monocot stem the vascular bundles are conjoint and closed, meaning they lack cambium and cannot undergo secondary growth, and they are scattered throughout the ground tissue rather than forming a ring. The option describing open bundles arranged in a ring fits the dicot stem, where cambium between xylem and phloem permits secondary growth, so it is the contrasting condition rather than the monocot one. Bundles containing only xylem without phloem do not occur in normal conjoint stem bundles, which always have both tissues. Radial bundles with alternating xylem and phloem are characteristic of roots, not of monocot stems. As stated in NCERT Class 11, Chapter 6 (Anatomy of Flowering Plants), monocot stems have closed, scattered vascular bundles. A comparative check confirms that scattered, cambium-less bundles uniquely identify the monocot stem against the ringed dicot pattern.