Rose Classifications

by Billie Flynn, Consulting Rosarian, Central Louisiana Rose Society

Information from the American Rose Society Handbook for Selecting Roses and The Official Registry And Checklist - 2nd Edition - Rosa

Information collected by Central Louisiana Rose Society Newsletter Editor Billie Flynn

Rosebud June 2020

In order for the rosarians to foresee the growth habit and provide proper care of the many different roses in their garden they must first identify the class to which each of their roses belongs. The class along with other information about each rose can be found by simply looking up the name of the rose in reference books such as the American Rose Society Handbook for Selecting Roses, or searching online here.

There are over 40,000 named roses, some no longer in commerce or in existence. In 1955, the International Cultivar Registration Authority appointed the American Rose Society international responsibility to define rose classifications according to origin and botanical characteristics, maintain the records of all registered roses and prevent the duplication of named roses. When a hybridizer registers the name of a rose it is the responsibility of that hybridizer to use the classification definitions described by the American Rose Society to designate the class to which the rose belongs.

The American Rose Society divided all roses into three main groups: Species (i.e. wild roses); Old Garden Roses (classes in existence before 1867); and Modern Roses (classes not in existence before 1867). These three groups were further divided into 37 classes according to their origin, growth characteristics and classification assigned by the hybridizer or introducer.

Classification Characteristics — The American Rose Society provides information to explain the distinction of rose classifications. (For lack of space, only the most often grown classes are defined in this newsletter)

Species Roses — Often referred to as “wild roses,” species roses are usually single-petaled (4-8 petals), once-blooming and have a bush size ranging from two 2 to 20 feet. They are listed according to their Latin name.

Old Garden Roses — In 1966, the American Rose Society defined old garden roses as those classes (not roses, but classes) that existed prior to 1867. Within the class of Old Garden Roses there are 22 subdivisions based on natural historical developments and characteristics. Among the most often grown old garden rose classes are:

Zéphirine Drouhin (Bourbon)

Souvenir de Malmaison (Bourbon)

Louise Odier (Bourbon)

* Bourbon — Developed from the hybrid chinas, these were the first repeat-flowering roses. They derive their name from the location of the first members of the class, the Ile de Bourbon in the Indian Ocean.

Old Blush (China)

Mutabilis (China)

Green Rose (China)

* China — This group’s most important characteristic is its ability to repeat bloom. The plants are variable in height, with relatively few thorns. The flowers tend to be borne in small clusters. China roses originated in Southeast Asia and are one of the most important historical groups of roses.

* Damask — These roses are best known for their intense heavy fragrance. Plants generally range in size from 3 to 6 feet. Some varieties are repeat blooming.

* Moss — Named for the mossy thorn growth on the peduncle just below the bloom and sepals, this group releases a pine-scented oleoresin when the moss is rubbed between the fingers. Some varieties are repeat blooming.

Mme Alfred Carrière (Noisette)

* Noisette — This classification originated in the United States by Philippe Noisette of Charleston, SC, who later introduced them in France when he moved there in 1817. Plants are large and sprawling, often reaching up to 20 feet tall. Blooms are produced in fragrant clusters.

Sombreuil, (Climbing Tea)

* Tea — Characterized as variable in height, with some of the best cultivars being Climbing Teas. Teas have large blooms on weak stems resulting in drooping or nodding flowers. This group is one of the immediate ancestors of the modern Hybrid Tea. They grow best when only lightly pruned.

The era of modern roses was established in 1867 with the introduction of the first hybrid tea, 'La France', by the French hybridizer Guillot. This variety was considered unique for their repeat bloom, upright growth habit, fragrance and color range as well as the elegant shaped buds and free-flowering character of a tea rose. Hybridizers were quick to recognize that planned parenthood (cross pollination of select roses) could evolve new flower forms, size, growth habit and colors. By the late 20th century, more than 10,000 hybrid teas had been hybridized with great success. Therefore, the following new classifications based on growth habit evolved.

Peace (Hybrid Tea)

* Hybrid Tea — Perhaps the most popular class of modern roses is the hybrid tea, easily recognized by the large shapely blooms containing 30 to 50 petals. Flowers are borne on long stems either singly or with several sidebuds. In 1945, the 'Peace' rose heralded the modern era of the elegantly formed hybrid teas. So dramatic was the overwhelming public acceptance and praise accorded this variety that its place in history was instantaneous. Since 1945, many thousands of new hybrid teas have been bred and introduced.

* Grandiflora - In 1954, the introduction of a rose bred from crossing the hybrid tea 'Charlotte Armstrong' with the floribunda 'Floradora' resulted in a carmine rose and dawn pink variety. It displayed not only the characteristics of a hybrid tea but also the ability to bear clusters or trusses and grow to a commanding height of 6 to 8 feet or more. To accommodate this variety, the class of grandiflora was born. 'Queen Elizabeth' had the distinction of being the very first member of this class.

* Floribunda — Second only to the hybrid tea and grandiflora in popularity, the floribunda is characterized by its profuse ability to bear flowers in large clusters or trusses with more than one bloom in flower at any one time. This class is unrivaled for providing massive, colorful, long-lasting garden displays. The distinct advantage of the floribunda is its ability to bloom continually whereas the hybrid tea exhibits a bloom cycle every six to seven weeks. Floribundas as a class are hardier, easier to care for than hybrid teas.

* Polyanthas are generally smaller but sturdy plants with large clusters of small 1-inch diameter blooms often used for massing, edging and hedges.

* Miniature roses have increased in popularity due to their novelty and versatility... Their average height is 15 to 30 inches with flower form and foliage which are indeed miniature versions of both hybrid teas and floribundas.

* Miniflora roses are a new classification adopted by the ARS in 1999 to recognize another step in the evolution of the rose, intermediate bloom size and foliage falling between miniatures and floribundas.

* Shrub (Classic & Modern) — Shrubs are easily characterized by their sprawling habit. There are five popular subdivisions within the class: hybrid kordesii, hybrid moyesii, hybrid musk, hybrid rugosa and shrub. They can grow from 5 to 15 feet or more in every direction given the correct climate and growing conditions. Noted for their hardiness, they are usually vigorous and produce large quantities of clusters of flowers. The unique group of roses hybridized by David Austin (often called English Roses) belong to this class. They resemble old garden roses in shape and form but are recurrent bloomers and often have fragrance.

* Large Flowered Climber, Hybrid Gigantea, Hybrid Wichurana — These varieties are dominated by their growth habit, long arching canes with the ability to climb up fences, over walls, and through trellises, arbors and pergolas if properly trained and tied. These varieties offer a wide range of flower forms, shapes and colors.

For more information about rose classifications visit:

https://www.youtube.com/watch/?v=ITuDKT5piww

http://hedgerowrose.com/types-of-roses/

https://en.wikipedia.org/wiki/Garden_roses

http://scvrs.homestead.com/TypesOfRoses.html

All photos by Rich Baer