Here is your free sample essay on Branching

An angiosperm pant is differentiated into root, stem, branch, leaf, flower and fruit. The mode of arrangement of branches on the stem is known as branching. Branching is of two types: lateral and dichotomous.

These are developed from the axillaries or lateral buds. The large branches are called boughs while the small ones are known as twigs. Branching brings about the shape of the plant. In caudex form, the stem is un branched bearing a crown of leaves at the top as seen in palm and coconut.

A plant is said to be excurrent where the apical bud grows indefinitely producing branching strictly in acropetalous order as seen in Polyalthia long folia. In deliquescent type, the growth of apical bud is suppressed while the lateral buds develop more vigorously, giving a spreading habit to the plant as seen in banyan.

A. Lateral branching:

This type of branching produces lateral branches. It is also called axillaries branching because it is developed from the axis. It may be racemose (monopodial or indefinite) or cymose (definite).

1. Racemose or monopodial branching:

In this case, the growth of the apical bud is indefinite giving rise to a straight stem. The lateral buds grow on the lateral sides of the straight stem in an acropetal succession.

The lowest branch is the oldest and longest. Gradually, it bears shorter branches towards the upper side assuming a pyramidal form or conical shape, e.g., Polyalthia long folia, Casuarina, etc.

2. Cymose branching:

The growth of the apical bud is checked while the side branches develop and grow forming a spreading habit. When the growth of the apical bud of the plant is checked, the lateral branches grow vigorously and the plant becomes dome shaped.

This gives a deliquescent form e.g., mango or jackfruit, etc. Based on the number of lateral strong branches produced, there are different types of cymose branching:

(i) Uniparous cyme:

Only one lateral branch is produced. So it is called uniparous or monochasial cyme. The uniparous type of branching is a succession of daughter axes fused together.

Therefore, it is otherwise called sympodial branching. When successive branches produced on the same side forming a helix, it is called helicoids cyme as in Saraca, but if these branching are alternate then it is said to be scorpioid cyme as in Vitis.

(ii) Biparous cyme:

Here, two lateral branches develop at a time from the axils of two opposite leaves at each node. This gives rise to a symmetrical shoot, said to be dichasium, e.g., Ervatamia. Sometimes, the terminal bud remains undeveloped and the branching looks like a dichotomy.

In this case, since there are two opposite leaves at each node, it possesses two opposite axillaries buds. Therefore, two symmetrical shoots are developed, e.g., Mirabilis Jalapa, Ervatamia divaricata, etc.

(c) Multifarious cyme:

The plants with more than two leaves at each node upon suppression of development of apical bud produce more than two branches at each node. Such a branching is called polychasial cyme, e.g., Croton sparsiflorus.

B. Dichotomous branching:

The terminal bud divides into two, producing two branches in a forked manner. It is common among the no flowering plants. It may be a normal or true dichotomy when two forked branches formed again continue to show similar branching again and again.

In some plants, after the bifurcation is made one half grows normally while the other half is suppressed. Successive suppression may be on the same side or on alternate sides. It is said to be sympodial dichotomy.

If the branches on one side only are suppressed, it is called helicoids dichotomy and the plants appear coiled. If the alternate branches to the left and right are suppressed, it is called scorpioid dichotomy.