Difference Between Monocot And Dicot Leaf

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Classification of Plants - Monocot And Dicot Leaf

A leaf is a lateral attachment to the plant stem which supports the main function of photosynthesis. It is an important structure of the plant in charge of feeding.

In Botany, the plants are classified based on various aspects. 

Cotyledon is the first significant part of the embryo to emerge from the seed and is formed during the process of embryogenesis along with its roots and shoots before germination. When the seed germinates, cotyledon becomes the embryonic first leaves of a seedling. Considering the number of cotyledons in flowering plants, they can be classified as Monocotyledonous or Monocots (species of plants with single cotyledon or embryonic leaves) and Dicotyledonous or Dicots (species of plant with two cotyledons). Apart from being different in the number of cotyledons, monocots and dicots exhibit various other characteristics of stem, roots, flower parts that distinguish them from each other.


Monocot Leaf

Monocotyledons or Monocots are flowering plants with seeds having a single cotyledon or embryonic leaf. There are about 60000 species of monocots found worldwide. Monocot leaves are slender and elongated with parallel veins. Compared to other forms of veins, in parallel venation, the veins are small in size with even smaller veins connecting them.

Monocots have flower parts in sets of three. Their roots are fibrous. A few examples of Monocots are Bananas, Palm trees, Grasses, water plantains, Lilies and Orchids.


Dicot Leaf

Dicotyledons or Dicots are flowering plants with seeds having two cotyledons or embryonic leaves. There are 175000 known species of dicots.

The leaves of a dicot plant have veins distributed in a net-like or reticulated pattern. In such leaves, the veins appear like a finely branched network throughout the leaf blade with thin veins reticulating between the major veins.

The flower parts in Dicots are tetramerous or pentamerous i.e in multiples of four or five. Dicots have a tap root system with a long deep primary root growing into finer secondary branches. 

Some examples for the Dicots are Oaks, Elms, Maples, Mango, Papaya, Radish, Rose, Castor and Guava.


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Difference Between Monocot and Dicot Leaf

Properties

Monocot Leaf

Dicot Leaf

Shape

Usually elongated and narrow

Dicot leaves are typically broad and round-shaped

Venation

Monocots have veins parallel to one another

Dicot leaves have veins that branch out from a single vein like a net

Leaf colour

The upper and lower surface of a monocot leaf is equally green

The upper surface of a dicot leaf is usually dark green and the lower surface is light green

Stomata

Monocot leaves have dumb-bell shaped stomata

Dicot leaves have kidney bean-shaped stomata

Distribution of Stomata

Monocot leaf is amphistomatic. Stomata are found in both the upper and lower epidermis

Dicot leaves are hypostomatic. The stomata are found only on the underside of the leaf

Arrangement of stomata

The stomata are arranged in parallel rows and are distributed uniformly on both the surfaces of a leaf.

In dicot leaves, the stomata are arranged randomly on the epidermis.

Mesophyll

In Monocot leaves, the mesophyll is single-layered 

Dicot leaves have two different mesophylls i.e Palisade mesophyll and spongy mesophyll. Palisade mesophyll cells are located beneath the leaf’s upper epidermis and Spongy mesophylls are located under the Palisade mesophylls

Motor or Bulliform Cells

The bulliform cells are the epidermal cells present in the upper surface of the Monocot leaf. They are large, empty and colourless, and present in the mid-vein region of the leaf

Motor cells are absent in Dicot leaves

Intercellular spaces

The intercellular spaces are small due to the compact arrangement of mesophyll cells

In Dicot leaves, the intercellular spaces are large due to the presence of loosely packed mesophyll cells

Symmetry

Isobilateral; wherein the surface is the same on both the sides of a leaf because of the presence of a single type of mesophyll cells 

Dorsiventral; in which two surfaces of the leaf differ from each other in appearance and structure because of the presence of two types of mesophyll cells

Vascular Bundles

There are many small and large-sized Vascular bundles present in a parallel pattern 

Vascular bundles are generally large in dicot leaves

Protoxylem 

In monocot leaves, the protoxylem elements are distinguishable as protoxylem lacuna

Dicot leaf (large vascular bundles) do not show differentiation into Protoxylem elements

Bundle Sheath

Monocot leaves may have a single or double layer of bundle sheath formed of coloured cells due to the presence of chloroplasts

The bundle sheath of a dicot plant is generally single-layered and is formed of colourless cells

Silica Deposition

Monocot leaves have a heavy deposition of silica in epidermal cell walls

Dicot leaves do not have silica deposition in the walls of epidermal cells

FAQ (Frequently Asked Questions)

1. What are the characteristics of a monocot plant?

Below is the characteristics of monocot plants:

  • The monocot plants have embryo with a single cotyledon

  • The flower parts are in multiples of three

  • Secondary growth is absent in a monocot plant

  • The vascular bundles of the stem are scattered

  • The roots in a monocot plant are adventitious

2. What is cotyledon?

A cotyledon is a very important part of an embryo that is inside the seed of the plant. It is also defined as an embryonic leaf in seed-bearing plants, one or more among which are the first to appear from a germinating seed. Amongst the flowering plants, the number of cotyledons present is one of the characteristics that is used in classification.

3. Is coconut tree monocot?

The coconut palm does not have any bark, secondary growth or branches. Therefore, botanically, it is not a tree. It is a woody perennial monocotyledon in which the trunk is its stem. Today, it is classified under monotypic with one species named Nucifera.