Morphology of stem : main charactieristics and types of stem


Stem is the most important portion of a plant. In this article I am providing morphology of stem. You will find main characteristics of stem, difference between stem and roots, types of stem and difference between under ground stem and root.

Stem is the main axis of shoot system of plants. Stem is the ascending part of shoot axis which is positively phototropic, negatively geotropic and develops from Plumule of embryo.

Characteristics of stem


The main characteristics of stem are as follows:

  1. Stem is an aerial part of plant which develops from the plumule.
  2. Stem are usually positively phototropic, negatively geotropic and negatively hydrotropic.
  3. Stem bears a terminal bud for growth.
  4. The stem is differentiated into nodes and internodes.
  5. The nodes posses appendages, i. e. , leaves, branches and flowers.
  6. Leaves and stem branches develop exogenously.
  7. The young stem is green and capable of performing photosynthesis.
  8. Axillary buds are found in the axis of leaves on the stem.
  9. Multi cellular hairs are found on the surface of stem.
  10. The branches of stem may end in a vegetative or floral bud.
  11. Stem exposes leaves, flowers and fruits to their most suitable position in the aerial environment for optimum function.


Difference between Root and Stem


The main differences between root and stem are:

  1. Roots develop from the radicle of embryo but stem develops from its plumule and epicotyl of embryo.
  2. The root is descending axis of plant whereas stem is ascending axis of the plant.
  3. Roots are non green and non photosynthetic except few aquatic plant but young stems are green and photosynthetic.
  4. Nodes and internodes are not found in roots but nodes and internodes are found on stem.
  5. Root does not bear buds whereas buds are present on stem.
  6. Roots are negatively phototropic but stems are positively phototropic.
  7. Roots are positively geotropic whereas stems are negatively geotropic.
  8. Roots are positively hydrotropic but stems are negatively hydrotropic.


Types of stems


According to the position on soil, there are three types of stems:

  1. Aerial stem s: All those stems which grow above the soil level are known as aerial stem.
  2. Sub aerial stems : Some stems are found beneath the soil surface in such a way that stem remains in contact with both the soil and the air.
  3. Underground stems : Stems of some plants remain underground and help in perennation, storage of food. Stems may be distinguished from the roots by the presence of scales, leaves and buds at the nodes.


Difference between underground stem and root


The main differences between underground stem and roots are:

  1. udder ground stem bears nodes and internodes whereas nodes and internodes are absent in root.
  2. Thin scale leaves are present in the nodes of under ground stem but scale leaves are not found in root.
  3. udder ground stem contains terminal and axillary buds but axillary buds are absent in root.
  4. Adventitious roots develop from nodes of underground stem whereas adventitious root are not found in root.
  5. Root hair and root cap are not found in under ground stem but root hair and root cap are main characteristics of root.


Article by Hakimuddin Kuwakhedawala
Hakimuddin Kuwakhedawala is based in India with over 15 years experience as a teacher. Teaching and writing are his passion. Most of the articles of Hakimuddin are related to education, exam, environmental problems, etc.

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