What are the Types of Cymose Inflorescence?Flame Institute

Inflorescence

The pattern of flower arrangement on the floral axis is known as inflorescence. Inflorescence is divided into two main types:

Racemose: In racemose types of inflorescence, the main axis grows continuously and flowers are present laterally on the floral axis. Flowers are present in an acropetal manner
Cymose: In the cymose type of inflorescence, the main axis does not grow continuously. A flower is present terminally on the main axis. The flowers are borne in a basipetal order. The main axis has limited growth

Other than these two, there are three special types of inflorescence present.

These are:

Hypanthodium: The main axis forms a cup-shaped structure with a cavity having both male and female flowers and a small apical opening. E.g. Ficus
Cyathium: Here the cup-shaped structure is formed from involucre of bracts. The single female flower is present in the middle, which is surrounded by numerous stalked male flowers. E.g. Euphorbia
Verticillaster: This type of inflorescence is typical of plants with opposite leaves. It has two clusters of sessile flowers developing from the two opposite axils of leaves. Each cluster has a dichasial cyme arrangement. E.g. Ocimum, Salvia

Difference between Cymose and Racemose inflorescence

S.No.	Cymose	Racemose
1.	The main axis terminates in a flower and has definite growth	The main axis continues to grow indefinitely
2.	Peduncle shows sympodial or multipodial growth	Peduncle shows a monopodial growth
3.	The flower is present apically in basipetal succession	The flowers are present laterally in acropetal succession
4.	The arrangement of flowers is centrifugal	The arrangement of flowers is centripetal
5.	The grouping of flowers is more common	The grouping of flowers is less common
6.	The first formed flower is at the tip of peduncle	The first formed flower is at the base of the peduncle
7.	The number of flowers is definite	The formation of flowers is indefinite or unrestricted
8.	Flowers bloom at a long interval	Flowers bloom at a short interval
9.	Newly formed fruits are protected by flowers	Newly formed fruits are not protected by flowers

Cymose Inflorescence

The cymose inflorescence is characterised by the presence of a flower at the apex of the flower axis. The growth of the main axis is limited and the lateral axis also terminates into flower and that limits the growth of the axis. Flowers are present in the basipetal succession, i.e. older flower is present terminally and the younger ones at the base. This type of arrangement is known as centrifugal with the older flowers present in the middle and the younger ones at the periphery.

Types of Cymose Inflorescence

There are four main types of cymose inflorescence:

Monochasial cyme
Dichasial cyme
Polychasial cyme
Cymose capitulum

Monochasial cyme: It is also known as uniparous cyme. The main axis terminates in flower and it produces one lateral branch from the base, which also terminates in a flower. Each lateral and subsequent branch also produces one lateral branch with a terminal flower. Monochasial cyme is further divided into two types:
1. Scorpioid: Lateral branches develop alternately on both sides of the axis e.g. Gossypium, Sundew
2. Helicoid: Lateral branches develop on the same side forming a helix e.g. Begonia, Heliotropium
Dichasial cyme: It is known as biparous cyme. The terminal peduncle terminates in flower. It gives rise to two lateral branches with terminal flower. Subsequent branches also behave similarly. E.g. Jasmine, Teak Saponaria
Polychasial cyme: It is known as multiparous cyme. Multiple branches arise at the base of the apical flower on the peduncle. The oldest flower is in the middle. E.g Calotropis
Cymose capitulum: In this type of arrangement the peduncle is reduced to a circular disc. The older flowers develop at the centre of the disc and the younger flowers at the periphery. This is known as centrifugal arrangement. E.g. Acacia, Mimosa