Spines vs. Thorns

Key Differences



Spines and Thorns Definitions
Spines
Thorns
Spines
Thorns
Spines
Thorns
Spines
Thorns
Spines
Thorns
Spines
Thorns
Spines
Thorns
Spines
Spines
A sharp, pointed structure that is a modified leaf or stipule is known as spine. Spines provide protection to the plant. It also helps during the dry or hot condition by reducing water loss because when a leaf is replaced by a spine its surface area is reduced. And the function of leaf that is photosynthesis is then performed by stem. Spines are not very deeply seated and they are not connected to the vascular system of the plant. Spines occupies the same position as the leaves and bear bud in the axil. So we can say that the spines are exogenous part of the plant which is formed from the tissues that are present externally. Examples of spines are: ocotillo forms a spine that is a fusion of the stem and lower portion of the leaf. In most of the euphorbia species the spines arises from the either side of the bud and leaf scar. In acacia species stipule spines are present, stipule spines are hollow and provide shelter to the pseudomyrmex ants. Spines of cactus plants are modified leaves or shoots located in the axil of a leaf. In cactus spines are found in groups which is called as areole.
Thorns
Modified branches or stem are known as thorns. They can be branched or simple. Thorns are woody, sharp, straight and pointed structures. Thorns also provide protection to the plant from herbivores. They also helps in climbing. Thorns are formed in the axil of the leaves in place of a bud on an ordinary stem the same as other branches. So they can only be seen at the node of plant. Thorns are very deeply seated in to the plant therefore they have connection with vascular tissues. Thorns are endogenous in origin because they arises from deeply seated tissues of the plant. Examples of thorns are: gleditsia triacanthos (honey locust) have branched thorns. Crataegus crus-galli (cockspur hawthorn) have unbranched thorns. In alluaudia, each pair of leaf is subtended by a thorn.