Question

What is manoxylic and pycnoxylic wood?

Answer 1

Hint: The wood is the secondary part of the plant body. Wood is the fibrous and porous structural tissue which is found in the stem and roots of the trees. It can be defined as the secondary xylem in the stems. It involves the movement of carbohydrates and water through it.

Complete answer:
We know that wood is the important strengthening and nutrient conducting tissue present in the trees. It is abundant in natural material. The wood is produced by both gymnosperms and angiosperms.

Depending on the compactness and the parenchyma the wood is divided into two types-
- Monoxylic wood- It is the compact wood which contains a large amount of parenchyma. The parenchyma contains starch grains. They have a large pith and cortex which has less amount of xylem tracheids or wood. This wood is not durable and cannot be used for commercial use. Example- Cycas
- Pycnoxylic wood- It is the compact and strong wood which contains a large quantity of xylem tracheids. They have a small cortex with pith that contains a small amount of parenchyma. It is highly durable and can be used commercially for construction purposes. Example- Pinus.


Note: The vascular system in the plant comprises xylem and phloem. The wood is formed as the result of the secondary growth in the plants. The oldest part of the tree is in the centre. The conducting wood is the young xylem which is known as the sap wood and once the tissue dies and the wood cells become hollow, it forms heartwood.