Difference Between Racemose And Cymose Inflorescence

Inflorescence can be broadly classified based on the following:

Number and position of flowers
Sequence of flower development
The nature of inflorescence branching

However, the common classifications of inflorescence are Racemose and cymose. Others include:

Cyathium
Verticillaster
Hypanthium

What Is Racemose Inflorescence?

Racemose is a type of inflorescence in which the main axis of flower continues to grow, producing lateral stalked or pedicellate flowers in acropetal succession. The younger flowers are present at the tip while older flowers are found at the base.

Types of Racemose Inflorescence

Spadix: A fleshy spike covered with spathe. An example is maize and banana.
Raceme: Flowers with pedicel and are in an acropetal arrangement. Example is mustard.
Catkin: compact unisexual spike often hanging. An example is Acalypha.
Corymb: All the flowers are arranged at the same level due to the slight shortening of peduncle and pedicel is slightly elongated of lower flowers. An example is candytuft and Hawthorn.
Umbel: Pedicilate flowers in which the flowers originate from the same place and reach the same level. An example is Centella and waxiflowers.
Spikelet: It is a compact spike with few flowers born on the axis referred to as rachilla and surrounded by two scales called glumes. An example is wheat.
Spike: flowers without pedicel and are in an acropetal arrangement. An example is Amaranthus and Barley.
Capitulum: It is actually a short spike where the flowers are directly placed on the peduncle and giving it a flower-like appearance. A smaller capitulum is called the head. Example is Dandelion, sunflower.

Characteristics Of Racemose That You Need To Know

Racemose refers to a type of flowering shoot in which the growing region at the tip of the flower stalk continues to produce new flower buds during growth.
In racemose grouping, the newly formed fruits are not protected by flowers since they lie towards the outside.
The arrangement of flowers in a group is centripetal, that is, the younger flowers are towards the center and the older towards the outside.
The flowers open at short intervals in the racemose inflorescence.
The first-formed flower of the racemose inflorescence occurs at the base of the penducle.
A single insect visit can pollinate a large number of flowers.
A lost growing point is rarely replaced in the floral axis.
The formation of flowers is indefinite or unrestricted.
Flowers arise laterally.
The floral axis or peduncle is monopodial.
The flowers are formed on all sides.
The grouping of the flowers is less common.
The bracteates flowers are borne in the axils of the bracts.
The arrangement of flowers is acropetal.

What Is Cymose Inflorescence?

Cymose is a type of inflorescence in which the main axis of flower has limited growth and it terminates into a flower. The older flowers are present at the tip whereas the younger flowers are found at the base of the axis.

Types Of Cymose

Cymose Capitulum: Here, the peduncle is reduced to form a disc-like structure. This disc bears sessile flowers with the oldest in the center and the younger ones towards the periphery.
Monochasial/Uniparous: The main axis ends in a flower and has one lateral branch. Example is Drosera.
Polychasial/Multiparous: The main axis ends in a flower and at the same time it produces a number of lateral flowers around. The oldest flower lies in the center and ends the main axis. Example is Calotropis.
Dichasial/Biparous: The main axis produces a flower at the tip and produces two branches simultaneously at a lower level both of which also end in flowers. This pattern of branching is further repeated. Example is Dianthus.

Characteristics Of Cymose That You Need To Know

Cymose refers to a type of flowering shoot in which the first-formed flower develops from the growing region at the top of the flower stalk.
The newly formed fruits are protected by flowers in cymose grouping.
The arrangement of flowers in a cymose head and other types of groupings is centripetal, that is, the older flowers are towards the center and the younger towards the periphery.
Flowers open at long intervals and the total flowering period is much longer in the cymose inflorescence.
The first-formed flower of the cymose inflorescence occurs at the tip of the peduncle.
A single insect cannot pollinate many flowers in one visit though flowers are grouped more frequently.
A lost growing point does not interfere much in the formation of more flowers.
A definite or restricted number of flowers are formed.
Flowers are actually terminal.
The floral axis is sympodial or multipodial.
The flowers can be restricted to one side only as in helicoids uniparous cyme.
The grouping of the flowers is more common.
In uniparous cyme the ‘’ bracts’’ when present, are formed on the side opposite the origin of flowers.
The actual arrangement is basipetal which is clearly visible in biparous and multiparous cymes.