What Is the Purpose of the Thorns on a Rose Bush?

Prickles, commonly regarded as thorns, protrude from a rose cane.

Mankind has been infatuated by roses and their thorns throughout history. In "The Nightingale and the Rose" by Oscar Wilde, the bird allows its heart to be pierced by a rose thorn, magically turning a white flowering rose to red through a trickle of blood. The abstract ideal of love's sacrifice was symbolized by a thorn. But in their natural environment, rose thorns serve a more concrete purpose.

Romance and Literature

"And he repents in thorns that sleeps in beds of roses," Frances Quarles 1592-1644

Centuries of romancing with rose thorns have been written by writers, poets and song composers. The purpose of the rose and its thorns in literature has been to symbolically portray the relationship of love, beauty and pain suffered in different life affairs. The enraptured and empathetic reader or listener in turn forms deep emotional and philosophical ties with the subject matter. So strong are these ties, that the world still chooses to disregard the anatomically correct terminology of the thorn.

Misnomer

The dropping fall foliage exposes thorny stems supporting rose hips.

If you've been pricked by a thorn from a rose bush, it would be more correct to say you've been "thorn-ed" by a "prick-led". The correct term for a rose thorn is prickle. Rose canes do not produce thorns. Despite the efforts of botanists to correct the faux pas, many refuse the proper title of prickle in preference to the term thorn.

Plant Physiology

The prickles of rose canes protect the bush and its flowers.

Different foliage have needle-like projections that are found mainly on rose plant stems. These types of piercing protrusions are known as thorns, spines and prickles. The three are mistakenly interchanged with each other by the non-scientific community. Botanist Brian Capon defines rose prickles as "woody epidermal outgrowths growing randomly" along the stem between the bud nodes. "Many are recurved downward to deter predators from climbing upwards."

The purpose of prickles, or rose thorns, is to protect the plant from predators. Although humans propagate roses for the purpose of continuance of the many species through modern cultivation, roses do not distinguish between the human caretaker and a Japanese beetle. Therefore, we are recognized as predators by the rose, whether nurturing the plant or picking flowers for a bouquet.

Risks to Humans

Although prickles are not poisonous, they can cause health complications with which gardeners and rose lovers alike should be familiar. Be diligent and watch that the site heals. Continuous irritation or swelling could be a sign of an infection or worse. A piece of the thorn could be broken off in the affected area. Thorns embedded in the flesh are not radiolucent, that is, not visible by x-ray and are difficult to detect. Surgery is needed to remove the foreign fragment. In a case study from Grand Rounds medical journal, such a case was reported. The ailment tenosynovitis was cited as the reaction of the body as the tip of a rose prickle was lodged in the flesh next to the bone in a patient's finger. After antibiotic therapy failed, a biopsy was performed, the fragment found and removed. The initial X-rays failed to show the culprit to be a rose prickle.

Thornless Roses

Thornless varieties of roses are readily available for spring or fall planting.

Rose canes can be be heavily laden with prickles such as hybrid rugosas or have sparse protrusions like many hybrid teas. There are varieties of rose bushes, old and new, that are tauted to be thornless. These varieties include "Lady Banks," "Zephirine Drouhin" and David Austin's "Mortimer Sackler." Technically, they are not completely without thorns, but the stems are much cleaner and easier to manage. To love a rose does not mean one must be pierced by its prickle.

References

• E-Med: A Cae of Rose Thorn Tenosynovitis
• "Botany for Garneners"; Brian Capon; 2010
• "The Nightingale and the Rose"; Oscar Wide; 1888