[Biology Class Notes] on Difference Between Thorns and Spines Pdf

It is difficult to spot the difference between thorns and spines based only on their appearance since they both look almost identical. To know what is the difference between thorns and spines, we must look at how these two are created from different parts of a plant. While the thorn is a modified stem, the spine is a modified leaf. At , we have created a comprehensive summary of spines, thorns, and pickles along with their differences. 

Spines

Spines are sharp, pointed structures on a plant and are modified leaves. They protect the plant from predators. An example of spines can be seen in the Opuntia plant where the minute leaves of axillary buds transform into spines. Another example is pineapple where the margin of leaves is modified into spines. 

 

Thorns 

Thorns are woody, pointed structures in a plant that protect the plant and help in climbing. They are modified axillary leaves and are different from both spines and prickles. Thorns may be branched or unbranched and are always subtended by a leaf.

 

What is the Difference between Thorns and Pickles?

Spines are structures that are sharp in nature and are pointed. They are part of the plant and are modified leaves. These provide protection of the plants from predators. An example of spines is observed in the Opuntia plant where the leaves or buds of the axillary transform into spines. Another example of such plants is pineapples which have the margin of their leaves modified into spines. Spines are thus modified leaves or stipules which are parts of the leaves and have extensions of the leaf veins. The spines have vascular tissues. They are also called petiolar spines or leaflet spines and even stipular spines which are examples of spines that develop as a leaf part that has midrib, petiole, and secondary veins. Spines are observed widely in the family of cactus. The cacti have a particular kind of spine that is of different origin and are called glochids. The glochids are small and deciduous with many retrorse barbs along the length of the plant. Thorns on the other hand are woody and pointed structures that protect the plant and also help them in climbing other surfaces. They are axillary leaves that are modified and they differ from prickles and spines. The thorns are either branched or not branched.

The terms prickles and thorns are often mixed and used interchangeably but there is a slight difference between thorns and prickles. 

• While thorns are formed from internal tissue (endogenous), prickles develop from external tissue ( exogenous). 

• Prickles develop from the epidermis and cortex of plant stems while thorns are modified branches.

• Prickles can also occur on leaves and protrude from the main veins of the leaf unlike thorns

• Prickles can also be seen on adventitious roots and some fruits unlike thorns

An example of prickles is the rose plant. 

Spines, thorns, and prickles all prevent the animals from eating the plant.

Let’s look at the difference between thorns and spines in detail.