The following is from the 2002 American Rose Society “Handbook for Selecting Roses”.
Reprinted by permission.

Species Roses

Often referred to as “wild roses,” species roses are usually single-petaled (5-12 petals), once-blooming and have a bush size ranging from 2 to 20 feet. They are listed according to their Latin name, beginning with R. for Rosa and can have common synonyms. For example, ‘R. foetida bicolor’ is known as ‘Austrian Copper’.

Old Garden Roses

In 1966, the American Rose Society defined old garden roses as those types that existed prior to 1867, the year of the introduction of the very first hybrid tea, ‘La France’. Within this generic definition a number of popular subdivisions exist based on natural historical developments and characteristics. The flower form can be quartered, cupped, imbricated or expanded, reflexed, globular or compact. After an initial spring crop of blooms, some varieties may produce no more flowers the rest of the year, but their hip production does add a different kind of beauty to the garden. The beauty of old garden rose often lies in the heavy fragrance they can impart to the garden. The most popular classes are:

Known as “white roses,” these plants are upright often climbing, have dense blue-green foliage and are disease resistant.

First repeat-flowering roses developed from the hybrid chinas. They derive their name from the locations of the first members of the class, the Ile de Bourbon in the Indian Ocean. Plant size can range from 2 to 15 feet tall. Repeat blooming.

These Dutch hybridized roses derive their class name from the fact the flowers often contain more than 100 petals. Plants are 4 to 8 feet tall and winter hardy. They are also referred to as “cabbage roses” and are featured in Dutch flower paintings of the 17th century. Once blooming.

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.

Hybrid China (Chinensis)
Plants are generally small ranging from 2 to 3 feet tall. Stems are often too weak to support the clusters of blooms, which have a spicy fragrance. Plants are not hardy and require winter protection in cold climates. Repeat blooming.

Hybrid Gallica
Plants are small (3-4 feet tall) and are winter hardy. Blooms are fragrant and come in brilliant colors. Once blooming.

Hybrid Perpetual
Popular during the 19th century, these roses are characterized by their repeat bloom, plant size (about 6 feet tall, upright), fragrance and color range (mostly pinks and reds).

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. Plants are generally winter hardy and 3 to 6 feet tall. Some varieties are repeat blooming.

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.

This small group of roses was derived from crosses involving hybrid gallica, damask, centifolia and hybrid china. They are small in stature (usually feet tall), repeat blooming and have very short peduncles. Class named in honor of the Duchess of Portland.

Modern Roses

The era of modern roses was established in 1867 with the introduction of the first hybrid tea, ‘La France’, by the French breeder, Guillot. This variety was considered unique for a number of important horticultural reasons. One, it possessed the general habit of a hybrid perpetual as well as the elegant shaped buds and free flowering character of a tea rose. By the late 20th century, more than 10,000 hybrid teas had been bred with great success. Introduction of ‘La France’ heralded the era of modern roses. Breeders were quick to recognize that planned parenthood could evolve new flower forms and size, growth habit and colors. Therefore, the following new classifications based on growth habit evolved.

Hybrid Tea & Grandiflora
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 side buds. 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.

In 1954, the introduction of a rose bred from crossing the hybrid tea ‘Charlotte Armstrong’, with a 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 & Polyantha
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 and more reliable in wet weather than their hybrid tea counterparts.

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

Miniature & Mini-Flora
These classes have increased in popularity due to their novelty and versatility. They can be used for edging beds, growing in containers and rockeries or even for taking indoors as temporary pot plants for decoration. The height of the average plant is about 15 to 30 inches, and flower form and foliage are indeed miniature versions of both hybrid teas and floribundas.

Mini-flora roses are a new classification adopted by the American Rose Society in 1999 to recognize another step in the evolution of the rose, i.e. intermediate in 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 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 Climbers
These varieties are dominated by their growing habit, long arching canes with the ability to climb (if properly trained and tied) up fences, over walls, through trellises, arbors and pergolas. These varieties offer a wide range of flower forms, shapes and colors.

Award Descriptions

James Alexander Gamble Fragrance Medal Winners
Awarded to outstanding, very fragrant roses by the ARS Prizes & Awards Committee.

World Rose Hall of Fame Winners (aka World’s Favorite)
Roses chosen by popular vote, on a triennial basis, by the Member Countries of the World Federation of Rose Societies.

American Rose Society Miniature Award of Excellence Winners
These new miniature roses were rated over a two-year period by ARS members at American Rose Society miniature test garden sites throughout the United States.

American Rose Center Trial Ground Winners
These new roses were evaluated by ARS members over a two-year period at the American Rose Society’s Trial grounds in Shreveport, LA.

All-America Rose Selections Winners
These roses were rated as exceptional by the AARS, a non-profit organization of U.S. producers and introducers. They were evaluated for two years in test gardens throughout the United States.