Rosa canina

Rosa canina
Rosa canina flowers are sometimes pink
Scientific classification
Kingdom:	Plantae
(unranked):	Angiosperms
(unranked):	Eudicots
(unranked):	Rosids
Order:	Rosales
Family:	Rosaceae
Genus:	Rosa
Species:	R. canina
Binomial name
Rosa canina L.
Synonyms
See text

Rosa canina, commonly known as the dog-rose, is a variable climbing wild rose species native to Europe, northwest Africa and western Asia.

It is a deciduous shrub normally ranging in height from 1–5 m, though sometimes it can scramble higher into the crowns of taller trees. Its stems are covered with small, sharp, hooked prickles, which aid it in climbing. The leaves are pinnate, with 5-7 leaflets. The flowers are usually pale pink, but can vary between a deep pink and white. They are 4–6 cm diameter with five petals, and mature into an oval 1.5–2 cm red-orange fruit, or hip.

Synonyms

From DNA analysis using amplified fragment length polymorphisms of wild-rose samples from a transect across Europe (900 samples from section Caninae, and 200 from other sections), it has been suggested that the following named species are best considered as part of a single Rosa canina species complex, and are therefore synonyms of R. canina:

• R. balsamica Besser
• R. caesia Sm.
• R. corymbifera Borkh.
• R. dumalis Bechst.
• R. montana Chaix
• R. stylosa Desv.
• R. subcanina (Christ) Vuk.
• R. subcollina (Christ) Vuk.
• R. × irregularis Déségl. & Guillon

Cultivation and uses

A botanical illustration showing the various stages of growth by Otto Wilhelm Thomé

The plant is high in certain antioxidants. The fruit is noted for its high vitamin C level and is used to make syrup, tea and marmalade. It has been grown or encouraged in the wild for the production of vitamin C, from its fruit (often as rose-hip syrup), especially during conditions of scarcity or during wartime. The species has also been introduced to other temperate latitudes. During World War II in the United States Rosa canina was planted in victory gardens, and can still be found growing throughout the United States, including roadsides, and in wet, sandy areas up and down coastlines. In Bulgaria, where it grows in abundance, the hips are used to make a sweet wine, as well as tea. In the traditional Austrian medicine Rosa canina fruits have been used internally as tea for treatment of viral infections and disorders of the kidneys and urinary tract. The hips are used as a flavouring in Cockta, a soft drink made in Slovenia.

Forms of this plant are used as stocks for the grafting or budding of cultivated roses. The wild plant is used for stabilising soil in land reclamation and specialised landscaping schemes.

Numerous cultivars have been named, though few are common in cultivation. The cultivar Rosa canina 'Assisiensis' is the only dog rose without prickles.

Canina meiosis

A tall, climbing Rosa canina shrub

Rose hips

Rose bedeguar gall on a dog rose

The dog roses, the Canina section of the genus Rosa (20-30 species and subspecies, which occur mostly in Northern and Central Europe), have an unusual kind of meiosis that is sometimes called permanent odd polyploidy, although it can occur with even polyploidy (e.g. in tetraploids or hexaploids). Regardless of ploidy level, only seven bivalents are formed leaving the other chromosomes as univalents. Univalents are included in egg cells, but not in pollen. Similar processes occur in some other organisms. Dogroses are most commonly pentaploid, i.e. five times the base number of seven chromosomes for the genus Rosa, but may be tetraploid or hexaploid as well.

Names and etymology

The botanical name is derived from the common names 'dog rose' or similar in several European languages, including classical Latin and ancient (Hellenistic period) Greek.

It is sometimes considered that the word 'dog' has a disparaging meaning in this context, indicating 'worthless' (by comparison with cultivated garden roses) (Vedel & Lange 1960). However it also known that it was used in the eighteenth and nineteenth centuries to treat the bite of rabid dogs, hence the name "dog rose" may result from this (though it seems just as plausible that the name gave rise to the treatment).

Other old folk names include dogberry and witches' briar.

Invasive species

Dog rose is an invasive species in the high country of New Zealand. It was recognised as displacing native vegetation as early as 1895 although the Department of Conservation does not consider it to be a conservation threat.

Dog rose in culture

The dog rose was the stylized rose of medieval European heraldry, and is still used today. It is also the county flower of Hampshire. Legend states the Thousand-year Rose or Hildesheim Rose, that climbs against a wall of Hildesheim Cathedral dates back to the establishment of the diocese in 815.

Further reading

• Flora Europaea: Rosa canina
• Blamey, M. & Grey-Wilson, C. (1989). Flora of Britain and Northern Europe. Hodder & Stoughton. ISBN 0-340-40170-2.
• Vedel, H. & Lange, J. (1960). Trees and bushes. Metheun, London.
• Graham G.S. & Primavesi A.L. (1993). Roses of Great Britain and Ireland. B.S.B.I. Handbook No. 7. Botanical Society of the British Isles, London.