Monocots (or monocotyledons) and dicots (or dicotyledons) are the two main types of flowering plants. They differ in morphological characteristics of leaves, stems, flowers and fruit of flowering plants.
|Embryo||The dicotyledons embryo has two cotyledons.||Monocotyledons have one cotyledon.|
|Leaf venation||Leaf veins are reticulated (branched).||Leaf veins are parallel.|
|Flowers||Petals in multiples of four or five. May bear fruit ( if tree)||multiples of three|
|Secondary growth||Often present||Absent|
|Stem and vascular system||Bundles of vascular tissue arranged in a ring. The vascular system is divided into a cortex and stele.||Bundles of vascular tissue scattered throughout the stem with no particular arrangement, and has no cortex.|
|Pollen||Pollen with three furrows or pores||Pollen with a single furrow or pore|
|Examples||Legumes (pea, beans, lentils, peanuts) daisies, mint, lettuce, tomato, oak, tree, etc.||Grains, (wheat, corn, rice, millet) lilies, daffodils, sugarcane, banana, palm, ginger, onions, bamboo, sugar, cone, palm tree, banana tree,grass|
|Root Pattern||Taproot system||Fibrous roots|
|Presence or absence of wood||both herbaceous and woody||herbaceous|
|# of seed leaves||2 seed leaves||1 seed leaf|
History of the Classification
The classification of flowering plants or angiosperms into two major groups was first published by John Ray in 1682, and later by the botanist Antoine Laurent de Jussieu in 1789, replacing the earlier classifications. According to this classification, flowering plants were divided onto eight major groups, the largest number of species belonging to monocots and dicots.
Seed Coats around embryo
The number of cotyledons differs in the two types of flowering plants, and forms the basis for the main classification of monocots and dicots. Cotyledons are the seed leaves of the embryo and contain nutrition for the embryo until it is able to grow leaves and produce food by the process of photosynthesis. Monocots have only one cotyledon while dicots have two.
Dicot vs Monocot Stem
The vascular system in dicots is divided into a cortex and stele, whereas in monocots these distinct regions are absent. The vascular system is scattered in monocots with no particular arrangement whereas in dicots the vascular bundles consists of primary bundles forming a cylinder in the centre.
The number of flower parts is different in the two groups. They occur in multiples of three in monocots and in multiples of four or five in dicots.
Venation of leaves
Leaf veins are arranged either in parallels through the length of the leaf or in a reticulate arrangement throughout the leaf. In most species monocots leaves have parallel arrangement whereas dicots have reticulate arrangement.
There is also a different type of pollen structure present in the two classes, monocots developed from plants with a single pore or furrow in the pollen, whereas dicots developed from plants with a three furrows in their pollens.
Roots can develop either from a main radicle or arise in clusters from the nodes in the stem, called adventitious roots. Monocots are known to have adventitious roots whereas dicots have a radicle from which a root develops. A fibrous root system, with several moderately branching roots growing from the stem, is common in monocotyledons. In contrast, dicots have a taproot system, a tapering root that grows downward and has other roots sprouting laterally from it.
Secondary growth is found in dicots but absent in monocots. Secondary growth helps in the production of wood and bark in trees.
Examples of Monocots and Dicots
There are about 65,000 species of monocots. Some examples include lilies, daffodils, grains, sugarcane, banana, palm, ginger, rice, coconut, corn and onions.
There are about 250,000 species of dicots. Examples include daisies, mint, pea, tamarind, and mango.
There are some exceptions to this classification. Some species belonging to monocots can have characters belonging to dicots, since the two groups have a shared ancestry.