The upcoming discussion will update you about the difference between dicot and monocot stem.
Difference # Dicot Stem:
1. Ground tissue in dicotyledonous stem is well-differentiated into extra-stelar and intra-stelar regions. Extra-stelar ground tissue is differentiated into three zones:—collenchymatous hypodermis, parenchyma and starch sheath; and intra- stelar ground tissue consists of pericycle—homogeneous or heterogeneous, large medulla and medullary rays.
2. In dicotyledonous stem vascular bundles are arranged in distinct rings—one or two. Bundles are collateral or bi- collateral but always open. So dicotyledonous stems increase in thickness.
3. Xylem is larger in dicotyledonous stem , with a few rows of vessels.
4. Phloem in dicotyledonous stem is composed of sieve tubes, companion cells and phloem parenchyma.
5. No sclerenchymatous sheath is present in dicotyledonous stem. Peri-cyclic fibres are found as bundle caps or continuous band.
Difference # Monocot Stem:
1. Ground tissue in monocotyledonous stem is not well-differentiated into distinct regions. Hypoderms is sclerenchymatous in the maize stem, the rest of ground tissue is usually parenchymatous in nature.
2. Vascular bundles are numerous and irregularly distributed in the ground tissue of monocotyledonous stem. Bundles are collateral but closed, and so monocotyledonous stems do not usually grow in thickness.
3. Xylem in monocotyledonous stem is smaller with only a few vessels.
4. Phloem in monocotyledonous stem has only sieve tubes and companion cells and hence, is much smaller.
5. In monocotyledonous stem sclerenchymatous bundle-sheath is present wholly or partly surrounding the bundle.