in some other organisms. Dog roses 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. Name 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. The Roman naturalist Pliny attributed the name dog rose to a belief that the plant's root could cure the bite of a mad dog. It is not clear if the dogs were rabid. According to The Oxford Dictionary of Phrase and Fable, the English name is a direct translation of the plant's name from classical Latin, rosa canina, itself a translation of the Greek κυνόροδον ('kunórodon'); It is known to have been used to treat the bite of rabid dogs in the 18th and 19th centuries. The origin of its name may be related to the hooked prickles on the plant that have resemblance to a dog's canines. It is sometimes considered that the word 'dog' has a disparaging meaning in this context, indicating 'worthless' as compared with cultivated garden roses. 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. The dog rose is a declared weed in Australia under the Natural Resources Management Act, 2004 as the plant out-competes native vegetation, provides shelter to pests such as foxes and rabbits, is unpalatable to stock, large shrubs are resistant to grazing, therefore do not get eaten by farm animals. The dog rose invades native bushland therefore reducing biodiversity and the presence of desirable pasture species. It is a biosecurity risk as it hosts fruit fly. Birds and wild fruit eating animals are the main cause of seed dispersal. The plant seeds can also be carried in the hooves or fur of stock animals. They may also be carried by waterways. In culture The dog rose was the stylised rose of medieval European heraldry. It is the county flower of Hampshire, and Ireland's County Leitrim is nicknamed "The Wild Rose County" due to the prevalence of the dog rose in the area. Legend states the Thousand-year Rose or Hildesheim Rose, which climbs against a wall of Hildesheim Cathedral, dates back to