The genus Rosa includes about 150 species, all of which are native to the Northern Hemisphere. Over the centuries, hundreds of rose varieties have been bred from the species. Many classification systems have been developed, but the system of grouping roses into eight categories was developed by the World Federation of Rose Societies in 1971. In the WFRS system, Old and Modern rose varieties are separated into groups. Old Roses are categorised as either Climbing and Non-Climbing. Modern Roses are similarly grouped and then further divided into Recurrent Flowering and Non-Recurrent Flowering categories.
Old garden roses are generally those developed before the 1867 introduction of La France, the first hybrid tea rose. The category also includes modern roses with old rose parents, like breeder David Austin's English Roses. The majority of Old Roses are non-recurrent. The Climbers category includes the American-bred Noisette roses, and climbing tea and climbing Bourbon varieties. Well-known Noisettes still commercially available include Champney's Pink Cluster, Mme Alfred Carriere and the pink-flowered Blush Noisette. Among famous Bourbon varieties are Zeherine Drouhin, with cerise blooms and few thorns; blushing white Climbing Souvenir de la Malmaison and pale pink Louise Odier.
This category includes the sweet briars (Rosa eglanteria), with their distinctive apple-scented foliage. Lady Penzance is the most famous sweet briar descendant, with single, salmon-pink blooms. Also in this category are Alba, China, Centifolia, Damask, Moss and non-climbing Tea roses. Famous Albas include white-flowered Felicite Parmentier and the pink Great Maiden's Blush. Centifolias, celebrated for their many petals, include the red Robert le Diable and fragrant pink Rose de Meaux. White-flowered Madame Hardy is the best known of the exquisitely scented Damask roses.
Non-climbing Modern Roses
This category has two sections -- non-recurrent and recurrent. Both the recurrent and non-recurrent groups include groundcover, miniature shrub and bush roses. Differences among the groups are mostly due to the growth habits of the plants. The recurrent category, which is extensive, includes a wide variety of large-flowered shrubs. Modern hybrid tea roses, like the celebrated Peace; and grandifloras, like Queen Elizabeth, are examples. In the 20th century recurrent shrubs eclipsed non-recurrent roses in popularity and the trend continues.
Climbing Modern Roses
The climbing category is similar to the non-climbing category in that recurrent bloomers outnumber non-recurrent varieties. Both groups contain large-flowered, cluster-flowered and miniature roses. The recurrent large-flowered category includes climbing versions of many famous bush roses like Fragrant Cloud. Non-recurrent large-flowered roses include summer bloomers like the blush pink Eden Rose and climbing version of the golden-amber Whiskey Mac.