There are countless different types of roses, so numerous that it takes an expert to know them all, if indeed anyone, even among experts has the knowledge of all types. So I am beginning this article with an account of how plants are classified, for understanding the botanical nomenclature will assist in understanding the plant's name. For the sake of brevity I will focus on the smaller categories.
While plants all have common names, all of them have scientific titles, and this rose is Rosa x hiberica. This locates it in the genus Rosa, a member of the enormous plant family known as the Rosaceae, which contains a huge proliferation of species and plenty of genera. The genus Rosa, like other genera [plural of genus] consists of a large range of closely related species. Species within a genus are closely related enough to interbreed, and often, though not always the hybrids are fertile. Note that Rosa hibernica capitalises the genus' name, but uses lower case for the species' name. This is normal botanical nomenclature. However, the insertion of an x between the two names indicates that it is a hybrid between two species within a genus; an x before the genus' name indicates an intergeneric hybrid, i.e. between species of different genera. These are usually infertile. If you see var followed by a name, e.g ....hibernica var. glabra, this indicates a distinction of a type within a species. A species name followed by a non-latin name in speech marks denotes a cultivar, which is a variety created and propagated by humans by vegetative propagation rather than by seed. I have not heard of any cultivars of the Irish Rose.
Hybridisation is common among wild plants, as plant seeds are no respecters of biological categories. Rosa hibernica is a cross between Rosa pimpinellifolia, the Burnet Rose, and Rosa canina, the dog rose. There may also be genes from native Irish wild roses that have over millennia contributed their share to hibernica's genetics. Sexual reproduction has the problem that desired varieties or species cannot breed true, as both parents contribute to the plant's genetics. This means that if you want to breed a true copy of the desired variety you must use asexual reproduction, known as vegetative propagation. There are several ways of doing this, but they vary from plant to plant. Roses are propagated by cuttings, so a cutting of Rosa hibernica would have been taken [probably several of them] and grown on in favourable conditions.
Rosa hibernica belongs to the group known as shrub roses, which means that they are in effect small trees. It can reach nine feet tall. The claim that Rosa hibernica only grows in Ireland is false. The same hybridisation has occurred independently in other parts of the British Isles, though rarely. The variety glabra was once thought to belong to hibernica, but has now been shown by genetic analysis to be a different hybridisation. Modern genetics has provided a great tool for analysing lines of descent.
Templeton's Rose is pink in colour and its flowers are followed in winter time by bright red hips. specimens are available for purchase from a small selection of plant nurseries.