Monocots and Dicots are the two lineages found in flowering plants called angiosperms. Angiosperms or flowering plants are the most diversified and successful plants on the Earth.

Over 250,000 herbs and shrubs are found to be in angiosperms. Monocots and Dicots differ in their stems, seeds, flowers, leaves, and roots. 

Generally, a cotyledon is also called a seed leaf within the embryo of a seed (embryonic leaf). It helps in storing nutrition and energy for the plant embryo that is required for it to germinate to become a photosynthetic organism. Angiosperms aka (also known as) flowering plants have either single cotyledon embryo called monocotyledon or double cotyledon embryo called dicotyledons

Definitions And Facts Monocots (Monocotyledons)

Monocots or Monocotyledons are angiosperms whose seeds contain only one embryonic leaf in them.  

A monocot flower called Tradescantia Pallida image pictures
Image: A monocot flower – Tradescantia Pallida 
  • Monocots have a thin and lengthy embryonic leaf in their seed. 
  • Monocot leaves are more elliptical and upright in shape.
  • Monocots have leaves amphistomatous in nature which means stomata is present on both upper and below surfaces.
  • Monocot leaves have vascular bundles that run parallel to each other. 
  • Monocot stems lack cambium which makes them herbaceous plants due to lower height gain.
  • Their stems have no separation between stellar and cortical regions.
  • Monocot stems offer a protective covering to new leaves. Monocot stems are juicy and unbranched as well.
  • Seeds are big and juicy. The largest seed, Coco-de-Mer, as well as the smallest seed, Orchid seed in the world, are monocots.
  • Normally, monocots have an epidermis with a thin cuticle, but they don’t have epidermal hairs.
  • Few of the most strategically and economically important monocots includes plants like bananas, turmeric, cardamom, asparagus. Some household decorative plants and flowers are like epiphytes, lilies, and tulips.
Monocot Root ( Horizontal Cross section ) and labeled diagram with parts image
Image: Monocot Root ( Horizontal Cross section ) and labeled diagram with parts.

Image Created with Biorender.com

Definitions And Facts Dicots (Dicotyledons)

Dicots or Dicotyledons are angiosperms whose seeds bear two embryonic leaves in them. 

a dicot flower called Hibiscus rosa-sinensis
Image: A dicot flower called Hibiscus rosa-sinensis.
  • The shape and size of dicotyledon leaves are different from a true plant’s leaves.
  • Dicotyledon leaves are broader and larger than the real leaves of a plant.
  • Embryonic leaves in dicots contain two types of mesophyll: palisade and spongy mesophyll. The palisade mesophyll lies beneath the leaf’s epidermis. It has the highest population of chloroplasts so it is the major site for photosynthesis. The spongy mesophyll lies beneath the palisade layer and it allows more diffusion of gases like oxygen and carbon dioxide due to spaces between its cells. Chloroplasts are present here further apart than in the palisade mesophyll layer. 
  • Hypostomatous leaves are present to conserve water and nutrients for dicots. Chloroplasts are more or only present on the deeper side of the leaf. 
  • Dicot leaves are not very linear in shape.
  • Dicot leaves have vascular tissues that form net-like veins. 
  • A ring of primary vascular bundles and cambium can be found in the dicot stem. 
  • Their leaves are round-shaped.
  • Dicot leaves feature a single, lengthy taproot that has further branchings of smaller roots to them.
  • Sepals can be found in dicots under the corolla called calyx ( usually green in color) in the form of a ring. 
Dicot Root ( Horizontal Cross section ) and labeled diagram with parts image
Image: Dicot Root ( Horizontal Cross section ) and labeled diagram with parts.

Image Created with Biorender.com

Differences between Monocots and Dicots 

Basis of ComparisonMonocotyledonsDicotyledons
DefinitionMonocots are angiosperms whose seeds only contain one embryonic leaf.Dicots are flowering plants whose seeds bear double embryonic leaves.
Other namesAnother name for monocotyledons is monocots.Another name for dicotyledons is dicots.
Form of GrowthMonocots are either mostly herbaceous or sometimes arboraceous.Dicots are equally either herbaceous or arboraceous.
Species Monocots are less diversified flowering plant species with only 60,000 plant species.Whereas Dicots are more diversified and successful flowering plants with about 200,000 species of them.
EmbryoOnly one cotyledon is present inside the embryo of a monocotyledon. Two cotyledons are existing inside the embryo of a dicotyledon.
Endosperm The endosperm is a structure surrounding the embryo, providing nutrition in the form of starch to it. In the case of monocotyledons, their seed has one large endosperm to feed the embryo.In the case of dicotyledons, their seed contains a tiny, single endosperm to feed the embryo.
Root SystemsMonocots have either adventitious or fibrous root systems.Dicots usually have a tap root system.
Stem1. Most monocot plant stems don’t have cambium between the xylem and phloem or a lateral meristem. Lack of differentiation into stellar and cortex regions.

2. Monocotyledons have fleshy as well as an unbranched stems.

3. The importance of a stem in monocots is to protect them, forming out of leaves.
1. Whereas cambium between vascular tissues (xylem and phloem) and lateral meristem is present in the stems of dicot plants. Has cambium differentiated into the cortex and stellar parts?

2. Whereas dicotyledons feature a branched and hard stem.

3. Dicot stems grow wider every 365 days.
Vascular Bundles 1. Within the stems of monocots, vascular bundles are scattered all over the ground parenchyma.

2. Monocot roots have 8-10 vascular bundles.
1. Within the stems of dicots, vascular bundles are organized into a ring in the stem.

2. Dicot roots have about 2-4 vascular bundles.
GrowthNo growth in monocots since no presence of cambium.Secondary growth occurs due to the presence of cambium.
Leaf1. Monocot leaves have a narrow and thin structure.

2. Amphistomatic leaves in monocots due to the presence of stomata on both upper and lower sides of the leaves.
1. Dicots usually have wider leaves but their shape and structure may vary due to different species.

2. Amphistomatous leaves in monocots due to the presence of stomata on either one side of the leaves.
VeinsMonocotyledon leaves have a parallel venation system.Whereas dicotyledon leaves have a reticulate venation system.
Flowers1. Flowers coming from monocotyledons are usually wind-pollinated due to their hairy structure.

2. The flower structure in monocotyledons is trimerous.
1. Flowers coming from dicotyledons are usually insect-pollinated due to their bright-colored petals.

2. Dicotyledon flowers are either tetramerous or pentamerous.
PollensMonocots have pollens which are monocolpate with a single furrow on its pollen tube. Dicots have pollens that are tricolpate with three or more furrows on their pollen tube.
GerminationSeed germination in a monocot is hypogeal.Seed germination in dicot is hypo or epigeal.
ExamplesExamples of monocots include bananas, asparagus, Lillies, and cereal.Examples of dicots include leguminous plants, roses, oak trees, and daisies.

Examples of Monocots 

Bananas

Bananas are ripened in the form of a plant. Bananas originate from the monocot family, showing no secondary growth and falling after the fruit has grown. Banana plant leaves have the same parallel venous structure. 

Lilies

Lillies fit in the most characteristics shown by monocotyledons. They are tiny and herbaceous, having adventitious roots. Their flowers are trimerous but they can come in many different shapes like trumpets, funnels, cups, bells, or flat shapes. 

Examples of Dicots 

Oak trees

Oak trees are non-magnolid dicotyledons that belong to a natural group of angiosperms that make two seeds when they germinate. They produce a fruit named, ‘acorn,’ which has about 1-3 seeds in it. Oak trees are becoming extinct though they have a long life span. 

Roses

Roses are one of the dicot flowers which have their leaves held on their stems. Most rose species have 5 petals whereas one exception, Rosa sericea has 4 petals in its flower.  Each petal is made of two lobes. These lobes are visible due to their longness and color which is usually pink or white and rarely yellow or red. 

References

  1. https://www.britannica.com/science/cotyledon-plant-anatomy
  2. https://www.researchgate.net/publication/316641848_Home_Science_Biology_Botany_Difference_Between_Monocot_and_Dicot_Difference_Between_Monocot_and_Dicot
  3. https://www.visiblebody.com/learn/biology/monocot-dicot/leaves
  4. https://microbenotes.com/monocotyledons-vs-dicotyledons/ 
  5. https://biologydictionary.net/monocot/
  6. https://uphomely.com/examples-of-dicot-plants#Oaktree 

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