We must admit it isn’t an easy task to differentiate monocots from dicots. But we can overcome this challenge by refreshing our knowledge on how monocots differ from dicots.
Click here for more information about dicots plants.
This knowledge saves us huge amounts of time when in the field endeavoring to identify plants using a key.
To make this work easier, scientists classified all flowering plants, also called angiosperms, into monocots and dicots. This was made possible by looking at the morphological differences of features such as flowers, leaves, stems, and roots.
So, let’s dive into what monocots are.
Monocot is a short form of monocotyledon, a class of flowering plants whose seeds sprout one embryonic leaf (cotyledon) during germination. For clarity, monocots must be contrasted with their opposite class of dicots (Dicotyledon).
Dicots are flowering plants that sprout two embryonic leaves. The seeds are usually rounded because they contain the endosperm that provides nourishment to the embryo plant.
Characteristics of a Monocot
While the obvious tell-tale sign of a monocot is the sprouting of just one leaf from its seed, there are other clues that help identify these plants.
The problem with most of these features is that they aren’t unique to monocots, nor are they universally present among all these plants. This means that no one characteristic is enough to describe what a monocot is but a combination of these features can help.
We start with the most common features.
- Embryo morphology
- Stem vascular structure
- Presence of plastid protein
Each seed plant’s embryo has one or more cotyledons, which absorb nutrients, and in some plants, these cotyledons act as the first leaves. With monocots, there’s only one cotyledon, while dicots have two.
Stem Vascular Structure
The arrangement of the stem’s vascular structure, or the atactostele, is another feature we focus on to describe a monocot plant.
Monocot plants’ stems have their vascular structure lacking the pith and the strands scattered in the stem but densely packed near its periphery. Again, extensive parenchyma in the cortex region surrounds these bundles and stores food material such as proteins, oils, and fats.
Additionally, these stems are usually unbranched and fleshy. While the stems of dicots are tough, branched, and grow wider annually, monocots’ stems don’t grow thicker from year to year.
Presence of Plastids Protein
Plant cells contain plastids, which can be used during the process of photosynthesis. If you prepare the material well and closely examine the plastid, you will see the crystalloid proteins in the plastid, and their shape is quite distinctive. In the case of monocots, the shape of the crystalloid proteins is triangular.
The inclusion of plastid proteins is a very reliable yet obscure feature of the monocot plants.
Other features we have looked at include:
The appearance of the flower petals is another feature to consider when distinguishing monocots from dicots. The flower petals of monocots are grouped in multiples of 3’s as seen in the image below.
The monocot flower usually has only one stigma, three sepals, and three petals. In most cases, the sepals and petals have the same color and are joined in a single ring. With this arrangement, the combination of petals and sepals appear like six petals and are therefore called tepals.
There are instances where flowers miss certain parts, such as petals, as in the case of grasses.
The leaf structure is another interesting aspect to note. The monocot leaves are amphistomatous, meaning the stomata are found on the leaf’s upper and lower sides.
Besides, the veins originate at the leaf base and run parallel to each other. When it comes to shape, the monocot leaves have an oblong or linear one, with only one leaf per node sprouting off the stem.
The root structure is another visible characteristic of monocots. These plants have a fibrous root system that spreads through the soil, forming a mat-like structure once the plant has matured. Of course, these roots perform their essential functions of supporting the plant and absorbing the nutrients from the soil to enable the plant to grow.
The shape of the monocot trunk is distinctively different from that of dicots. The monocot plants don’t have branches and don’t grow large. To believe this, we just look at the coconut trees around us and compare them to mango trees.
Examples of Monocots
The University of California Museum of Paleontology classifies palm trees as monocots. While it’s generally believed that monocots don’t grow wood, palm trees are an exception.
According to the University’s description, palm trees do not grow wood but instead receive ‘upright’ support from overlapping leaves that wrap around the stem. To provide a strong bond, the leaves wrapping around the stem are thickened by parenchyma cells and prop roots, which grow from the stem and tap into the soil, offering the needed support for the plant.
Other than this, the plant is considered a monocot because of its long leaves.
We enjoy the blossoming daffodils as they usher in Spring and add beauty to our gardens. These bulbous perennials are found in most North American areas, although they can be planted in any zone. Usually, daffodils produce showy yellow or white flowers with six petals. Sounds familiar? Of course, these petals are in the multiples of 3’s! A characteristic of a monocot.
Moving on, a daffodil is a monocot because it has narrow leaves whose veins are parallel to each other and sprouts only one leaf during germination. And we can’t fail to mention its fibrous root system that grows off the bulb and spreads in the soil in search of nutrients and moisture.
Additionally, the leaves of daffodils are narrow-shaped, long, and clustered around its base, but their veins run parallel to each other, originating from the base. This is a common characteristic of all monocot leaves.
This spring-blooming popular garden flower has large and bright flowers that are usually white, yellow, red, or pink.
Why is it a monocot?
This plant is a monocot because it exhibits the characteristics of a monocot. Its leaves have parallel veins while the petals are grouped in the multiples of 3’s. What of the leaf shape?
The leaves are long and skinny akin to those of grass and are produced in twos or threes. Usually, these leaves are clustered at the base of the plant. Interestingly, once a tulip has flowered, it dyes back to an underground storage bulb.
Even when winter’s icy grip is unceasing, the resilient Crocus still manages to push through the ice and brighten our gardens. Standing 2 to 4 inches above the ground, this perennial flower injects life in the bleak late-winter landscape. The strong perfumes emanating from the crocus flowers attract bees that buzz the garden, adding life to it.
The Crocus finds its position on this list of monocot plants because of its long green leaves whose veins run parallel to each, originating from the plant’s base.
Also, the flower’s petals are in multiples of 3’s, while the roots are fibrous and form a mat-like structure as they spread in the soil. As the bulb sprouts its embryonic leaves, we can see that it only has one embryonic leaf.
Lilies are beautiful flowers and are well-known highly-prized ornamental plants that are also highly hybridized. While these flowers come in an array of colors, the number of petals stands at six, admitting this plant into the group of monocots. Lilies are true garden stars that offer real value with little effort. They occupy little space in the garden but offer fabulous colors and create a strong impact.
While at that, Lillies have a fibrous root system that helps them obtain nutrients and moisture from the soil. Also, we find that the leaf veins are parallel to each other while showing only a single seed leaf emerging after germination.
The iris flower comes in a wide range of beautiful and magical colors. While its origin has been described as divine, this June bloomer is rugged, easy-to-grow, and reliable.
The Iris has distinctive six-petaled flowers with three outer hanging petals (falls) and three inner upright petals (standards).
This plant is a monocot because its flowers are multiples of three while the leaf venation is parallel. The veins are large, easily visible, and extend the length of the (usually) linear leaves. Looking at the roots, we find a fibrous root system that enables the plant to grow and anchor it firmly in the soil.
Garlic is a common feature in our kitchens and can grow in the kitchen garden without any problems. Its health benefits can’t be overstated here. It’s a species of the onion genus with its origin traced to Central Asia. It has been used for seasoning worldwide for a long time, making it a common ingredient in many household foods.
One cotyledon starts to emerge from the soil immediately when the plant begins to grow. Additionally, the leaves spot the trademark visible parallel veins. To crown it all, its fibrous roots confirm that indeed this plant is a monocot.
Asparagus is a common plant that we meet in Spring. Its ferny foliage makes an excellent ornamental, making this perennial a must-have in the garden. Luckily, Asparagus can grow in all regions, although it’s best suited in cooler regions with longer winters, considering that it stays productive for long.
Classified as a monocot, Asparagus has leaves that have parallel venation as well as a fibrous root system. As the plant emerges from the soil during germination, only a single leaf plate appears if you planted the seed.
As for the root system, Asparagus has a fibrous system that’s constantly increasing and helps the plant absorb water and nutrients and act as storage for the nutrients and water.
It’s a common monocot because its seed comprises a single cotyledon, while the roots have a fibrous system. Besides, the roots are fibrous, and the leaves have parallel venation compared to those of dicot plants. And just like all monocots, rice has a single embryonic leaf during germination.
Also known as maize, corn is a popular staple food for many households across the globe. Its total production surpasses that of other grains such as wheat and rice.
To understand corn, we must give a brief description of it. The plant’s leafy stalk produces pollen inflorescences, separate from ovuliferous inflorescences or ears that produce kernels, also called seed or fruit.
With its seed having only one cotyledon, which can’t easily be split, and a single first leaf after germination, corn is truly a monocot plant. And that isn’t all. The plant has long and narrow leaves whose veins run parallel to each other.
Main Differences Between Monocots and Dicots
Having looked at examples of monocot plants, let us examine, in brief, how they differ from dicots.