The following points highlight the two types of branching of stems. The types are: 1. Racemose Type 2. Cymose Type.
Branching of Stem: Type # 1. Racemose Type:
In this type of branching the growth of the main stem is indefinite, i.e., it continues to grow indefinitely by its terminal bud and gives off branches in acropetal succession. Here the lower branches are older and longer than the upper branches, e.g., Polyalthia, Casuarina, Eucalyptus, etc.
Branching of Stem: Type # 2. Cymose Type:
In such type of branching the main axis or the stem does not grow indefinitely due to the limited growth of the terminal or apical bud. Here the growth is definite, and the main stem produces one or more lateral branches which grow more vigorously than the terminal one. The process may be repeated again and again.
The cymose branching may be sub-divided as follows:
1. Uniparous cyme and
2. Biparous cyme.
1. Uniparous Cyme:
In such type, only one lateral branch is produced at a time and the branching is known as uniparous or monochasial.
It is further subdivided into two types:
(a) Helicoid cyme and
(b) Scorpioid cyme.
(a) Heiicoid Cyme:
Here the successive branches develop on one side only, e.g., in Saraca indica.
(b) Scorpioid Cyme:
Here the successive lateral branches develop on alternate sides, forming a zig-zag, e.g., in Vitis vinifera.
2. Biparous Cyme:
In such type of cymose branching, two lateral axes develop at a time, and it is called biparous or dichasial cyme, e.g., in Mirabilis, Viscum, Stellaria, etc.