Roses can be either grouped according to their shape (shrub, climber, ground cover) or according to their origin. Categroization according to origin is not an exact science, but they can be roughly grouped into three main groups: Species roses, antique roses and modern roses, which then are grouped into numerous sub-categories.
Species roses are, as the name implies, wild species and their cultivars that are not greatly hybridized. There are around 150 species of roses native to the northern hemisphere and often there is quite a lot of variation within species. These roses are the ancestors of all garden roses. The species that are most widely grown here in Iceland are Rosa pimpinellifolia, Rosa rugosa, Rosa pendulina, Rosa moyesii and Rosa sweginzowii. R. pimpinellfolia and Rosa dumalis are rare natives to Iceland and are both protected species. Neither is a good garden plant.
Antique roses, or old garden roses, are garden roses which originated before 1900. It is not a line chiseled in stone though, but can vary from the late 19th century to the mid 20th century. Most of them are single bloomers, at least the ones that can be grown in Iceland and most have white or pink flowers. The oldest cultivated roses are the China roses which originated in China around a 1000 years ago. They reached Europe around 1750. The tea roses also originated in China and reached Europe early in the 19th century. Both groups are tender and won't grow in Iceland. The Noisette roses originated from a hybrid between R. moschata and a China rose. They are climbers with large clusters of small flowers. They are most likely too tender for Icelandic conditions. The oldest European cultivars have been traced back to 1400.