Most often when people consider sending or receiving flowers with romantic meaning, the first flower that comes to mind is the rose. Roses are traditionally sent on first dates, anniversaries, to say "I'm sorry," or to express something you can't find the words to say. The rose is known for its soft, velvety petals, sweet fragrance, and symmetrical beauty. But when you receive a rose, you may end up getting pricked by one of the many thorns on the stem. Many people wonder why roses have thorns while being perceived as the gentlest flower.
One explanation is that thorns enable plant species to protect themselves, but there is another reason that helps explain why roses "have" thorns, rather than having them by chance. Thorns enable the plant to survive. It's a combination of how roses evolved and their current genetic makeup. Although roses appear beautiful despite their thorns, it's actually because of their thorns that they have thrived and become so beautiful. Thus, knowing why roses have thorns tells a larger story about how plants have evolved, how they adapt to different environmental stresses, and why they thrive under those conditions.
Additionally, the relationship between rose thorns and their survival may go unnoticed until you compare different species of roses. You may notice that one rose species has many thorns, while another seems almost smooth. This leads to the often-asked question: “Why do some roses have more thorns than others?” The answer lies in how species evolved from their common wild ancestors, the environmental stresses they experienced, and the trait variations humans have cultivated over time.
Thorns or Prickles, What’s the Difference? A Botanical Clarification
At first glance, rose stems appear to have a large number of spiny structures. The term "thorn" is commonly used, but from a botanical perspective, roses have prickles. This distinction matters for understanding their evolution.
In botany, a true thorn is a modified branch, arising from deep within the plant's structure. Prickles, however, are sharp points that grow from the outer skin, or epidermis, of the stem. They can be broken off without damaging the plant itself. This classification helps scientists understand the different evolutionary paths taken by various plants.
Understanding this explains why rose stems behave the way they do. It also clarifies why roses evolved this specific form of protection. In short, roses chose flexibility over rigidity- a design that suits survival.
More Than Defense: What Rose Prickles Actually Do
While their primary role is to deter herbivores and protect the plant from predators that might eat the leaves and flowers, prickles serve other small but important roles.
-
Prickles Serve as a Physical “No” to Creatures Who Want to Eat Us
An obvious function is protection from herbivores. The rose plant species that had the most effective prickles survived and reproduced, passing on those genes to the next generation over millions of years.
-
Managing Water and Providing Support
Prickles can help reduce water loss and, in some cases, aid in water retention. For climbing rose species, curved prickles act as hooks, helping the plant attach to supports - a simple but effective climbing mechanism, different from true vines.
-
The Genetic Answer Behind the Prickles
Recent research published in the journal Science (August 2024) has delved into the genetic origin of these structures. Scientists from Cold Spring Harbor Laboratory and international collaborators have studied the genes responsible for prickle development. They identified a key gene family, known as LONELY GUY (LOG), that controls the growth of these prickles. This research offers new insights. It turns out that the same family of genes is involved in creating sharp points in different plants like roses, blackberries, tomatoes, eggplants, and others. This is a fascinating example of convergent evolution, where different species independently evolve similar traits (like prickles) for similar needs (like defense). The authors found that while the trait is similar, the exact genetic pathway can vary, showing the incredible variation in nature's toolkit. This discovery in crops and wild plant species opens up the possibility for scientists to control or modify such traits in cultivated plants, including creating prickle-free varieties.
-
Benefits of Nature's Creation
The combination of these functions is what has allowed roses to retain dense prickles after millions of years of evolution. Because these prickles provide protection, help manage resources, and aid adaptation, roses have become sought after worldwide. It's an example of how nature creates multi-purpose tools for survival.
Utilizing Roses at Home and in Floral Design: Practical Applications
Although roses seem to transition effortlessly into finished bouquets, their desired presentation requires purposeful know-how and respect for the anatomy of the stem and flower. Rose prickles can be uncomfortable to handle.
-
Preventing Damage to Rose Stems When Working with Fresh Roses
When using fresh roses, protecting yourself from prickles is essential. Wearing gloves is the most effective method. If prickles must be removed, careful snapping is better than scraping, which can damage the stem.
-
Comfort First When Choosing Roses
There is significant variation in the prickles of different species and cultivars. Many modern roses have fewer or softer prickles, making them easier to work with. This is important when choosing roses for events.
-
The Proper Way to Maintain Fresh Flowers
Professional florists prepare each rose by hand, handling each stem with care to ensure both the safety of the rose and the florist.
-
An Alternative to Rose Care
If you enjoy roses but don't want the hassle, preserved or “forever” roses provide a great alternative. They hold their natural shape and color for up to 2 years with no water or care, and they have no prickles to remove.
Perfection Hidden in Every Detail
The perfect rose is a blend of nature, time, and need. The things we see as sharp thorns are really how the rose keeps itself safe, creates a habitat, and has the ability to adapt to changes, all while maintaining its graceful shape. Through science, we have confirmed that even the small parts of a rose are regulated by very specific genetic rules. Therefore, nothing on a rose is by chance.
When you send a bouquet to someone, you are not just giving them a flower; you are also sending a beautiful representation of strength and artistry. Art Flowers LA creates arrangements with this in mind. It is our goal to ensure that each arrangement is made from stems that are thoughtfully crafted by our skilled florists so that they remain fresh as well as comfortable and visually appealing to the recipient. Whether you choose classic fresh-cut roses or long-lasting preserved roses, you can be assured that your bouquet respects the artistry of nature and is beautifully made into a gift that says so much without saying a word.
FAQ
What causes excessive thorns on roses?
Excessive prickles (often described as "excessive thorns") are most commonly a symptom of Rose Rosette Disease (RRD), a serious viral infection spread by eriophyid mites. It causes witches’ broom (dense clusters of distorted shoots), thickened stems, excessive thorniness, red/yellow distorted leaves, and eventual plant decline or death. Other possible causes include environmental stress, certain herbicides, or genetic variation, but RRD is the primary culprit for sudden excess prickles.
Do some roses have more thorns than others?
Yes, significantly. Prickle density, size, and shape vary widely among species, cultivars, and even individual canes due to genetics, environmental stresses, and human selection. Wild roses often have denser, sharper prickles for survival, while many modern hybrid roses (especially for cut flowers) have been bred for fewer or softer prickles to make handling easier.
What type of rose has the most thorns?
Among the prickliest are certain wild or heirloom varieties, such as:
- Rosa minutifolia (often considered one of the world’s thorniest roses, with incredibly dense, fierce prickles and tiny leaves).
- Some Rugosa roses (Rosa rugosa) and vigorous climbers like ‘Kiftsgate’ (Rosa filipes) or ‘Mermaid’.
- Prickly Wild Rose (Rosa acicularis) and similar natives with dense prickles, especially on lower stems.
- Certain robusta or heirloom moss roses also rank high for prickle density.
Why do roses have thorns on their stems?
Roses have prickles (not true thorns) on their stems primarily for defense against herbivores, but they also aid in climbing (hook-like shapes), reduce water loss, offer minor temperature protection, and provide structural advantages in wild environments.
