Have you ever pierced yourself with the thorn of a rosebush? Certainly not. Many people don't know, but rose bushes don't have thorns, and yes aculeus. But, do you know the difference between a thorn and a pimple?
→ What is a thorn?
Thorns are generally defined as hard, dry structures found in vegetables.. They are sharp and are not able to carry out the photosynthesis process. The spines are also characterized by having vascular tissue, that is, tissue capable of transporting raw sap and elaborated sap.
thorns can be stem modifications and leaf. In cacti, for example, we have thorns that are modified leaves. In these organisms, thorns also help to prevent excessive water loss. It is noteworthy that in cacti, as thorns do not carry out photosynthesis, this process is carried out on the stems. In the lemon and orange trees, in turn, we find thorns that are stem organs.
→ What is an Aculeus?
On roses, there are thorns and no thorns
The aculeum, unlike the thorn, is neither a foliar nor a stem modification. It is usually a small, pointed projection of normally epidermal origin. Also unlike the spines, the aculeus does not have vascular tissue. In this case, a more classic example is the rose, which, therefore, does not have thorns, but these structures called aculeum.
→ What do thorns and aculeus have in common and what are their differences?
As we have seen, the spines and needles are different structures in terms of origin, since the spines have a foliar or stem origin and the needles have an epidermal origin.. It's easy to see the difference between these two structures when trying to detach them from a plan. The spine is difficult to be removed, and the needle is easy to remove, as it is a more superficial structure.
Despite their differences, aculeus and thorns have functions in common. Both thorns and thorns are important in the plant's defense against herbivory. An interesting relationship can be seen between ants and a plant species known as acacia. In this case, the thorns become shelter for the ants, which end up attacking any herbivores that try to eat the plant.
