17 Difference Between Monocot And Dicot Stem (With Pictures)

Plants whose seeds contains only one cotyledon or embryonic leaf is referred to as monocotyledon or simply monocot. On the other hand, a dicot is a flowering plant with an embryo that bears two cotyledons (seed leaves).  In this article, we will discuss about the difference between structure of a monocot stem and a dicot stem with reference to their vascular bundles. The basis of comparison include: arrangement of vascular bundles, number of vascular bundles, sclerenchymatous  bundles, ground tissue differentiation, protoxylem and metaxylem, vascular tissue life cycle, secondary growth, medullary rays, phloem parenchymas, silica deposition, hollowness in the stem, secondary growth

Monocotyledonous Stem

The following points highlight the internal structure of a monocot stem:

1. Monocot plant is characterized by presence of scattered vascular bundles throughout the ground tissue.
2. The vascular bundles are numerous and are of different sizes. They are smaller towards the outside and larger towards the center.
3. Due to absence of vascular cambium in between phloem and xylem, the vascular bundles in monocotyledonous plant stem are closed.
4. A sclerenchymatous bundle sheath is generally present on the outside of each vascular bundle.
5. The vessels are oval or round and are arranged in a Y-shaped like manner.
6. Ground tissue is differentiated into stelar and extra-stelar tissues.
7. In monocotyledonous stem, each vascular bundle has only two metaxylem elements.
8. The hypodermis is made up of non-green sclerenchyma fibres.
9. The first formed vascular tissues continue functioning throughout the life of plant.
10. The ground tissue is not differentiated into different cells; instead it is a mass of similar cells.  
11. Secondary growth in monocotyledonous plants is conspicuously absent.
12. The stomata of dicotyledonous plant have dumb bell-shaped guard cells.
13. In all monocotyledonous stems, medullary rays between vascular bundles for radial conduction are absent.
14. The stems of monocotyledonous plants show a little increase in diameter with age.
15. The stem of monocotyledonous plants is usually hollow in the center with exception of maize plant stem.
16. No phloem parenchymas are present in monocot stem.
17. There is silica deposition over the epidermis of the monocot stem.

Dicotyledonous Stem

The following points highlight the internal structure of a dicot stem:

1. Dicot plant stem is characterized by presence of vascular bundles arranged in rings around the pith.
2. The vascular bundles are fewer in number and all are uniform in size.
3. Due to presence of cambium in between phloem and xylem, the vascular bundles of a dicotyledonous plant are open.
4. There is no sclerenchymatous bundle sheath present on the outside of a vascular bundle.
5. The vessels are polygonal in outline and usually arranged in chains or rows
6. Ground tissue is differentiated into stelar and extra-stelar tissues.
7. Each vascular bundle of dicotyledonous stem has many protoxylem and metaxylem elements.
8. The hypodermis is made-up of collenchymas which is green in color.
9. The older vascular tissues stop functioning after some time. They are replaced by younger vascular tissues.
10. The ground tissue is differentiated into cortex, endodermis, pericycle, pith etc.
11. The dicotyledonous stem shows secondary growth due to the formation of secondary vascular tissues and periderm.
12. The stomata of dicotyledonous stems have kidney-shaped guard cells.
13. In dicotyledonous plants medullary rays are found in between vascular for radial conduction.
14. The stem of dicotyledonous plant shows increase in diameter with-age.
15. The stem of dicotyledonous plant is always solid. No hollow spaces.
16. Phloem parenchyma is present in dicot stems.
17. There is no silica deposition in the stem of dicot plants.

The Difference Between Monocot And Dicot Stem In Tabular Form