The rose, a globally cherished flower of the genus Rosa, has been cultivated for thousands of years. The question of how many varieties exist is complex because it involves differentiating between the species that occur in nature and the vast number of hybrids created by human intervention. Understanding the total count requires distinguishing between foundational wild roses and the ever-growing population of named cultivars.
How Rose Classification Works
The sheer quantity of roses available is best understood by separating natural species from cultivated varieties. In the wild, the genus Rosa contains approximately 150 to over 300 recognized species, which are the original forms of the plant. These wild roses are the genetic ancestors of every garden rose grown today, and they are sometimes referred to as species roses.
The massive number of varieties comes from the world of hybrids and cultivars, which are plants bred by crossing different species or existing cultivars. These man-made varieties are officially registered and named, and their number is estimated to be well over 37,000 globally. This enormous number is constantly increasing as breeders introduce dozens of new roses each year to the market.
The American Rose Society (ARS) acts as the International Cultivar Registration Authority for roses, tracking and recording new introductions worldwide. This registration process ensures that each unique variety receives a distinct name, often consisting of a buyer-friendly name or a standardized code. The registry is essential for organizing the immense diversity resulting from centuries of hybridization efforts.
The Three Historical Rose Groups
To organize this vast collection of varieties, experts have grouped them into three main historical categories: Species Roses, Old Garden Roses, and Modern Roses. Species Roses are the wild forms, characterized by their simple, five-petaled flowers and a tendency to bloom only once per season. They are the foundation upon which all other rose types were built.
The second group, Old Garden Roses (OGRs), includes all cultivated roses that existed before 1867. This category often features varieties known for their intense fragrance, full, cupped bloom forms, and high degree of cold hardiness. Examples include the Gallica, Damask, and Alba roses, many of which were popular long before the 19th century.
The year 1867 serves as the formal dividing line because it marks the introduction of ‘La France,’ the rose considered to be the first Hybrid Tea. All rose varieties whose class was developed after this date are classified as Modern Roses. This shift reflected a change in breeding focus, emphasizing repeat-flowering ability and the long, elegant bloom shape now common in florist roses.
Popular Types of Modern and Old Garden Roses
The Modern Rose category is dominated by the Hybrid Tea, which remains the most popular type of rose worldwide. These varieties are prized for their large, high-centered blooms carried singly on long, straight stems, making them the standard choice for cut flowers. They were bred by crossing the more robust Hybrid Perpetuals with the elegant, repeat-flowering Tea roses.
Another widely grown modern type is the Floribunda, a name that literally means “many flowering” in Latin. Floribundas produce abundant clusters of smaller blooms on shorter stems, offering a continuous display of color that is excellent for mass plantings and borders. They generally possess greater disease resistance and hardiness compared to their Hybrid Tea cousins.
Climbers and Ramblers represent a growth habit used to add vertical interest to a garden. Climbers have stiff, arching canes trained along arbors or trellises. Ramblers typically produce long, flexible canes and often feature one massive bloom period. Many Hybrid Teas and Floribundas have climbing forms that share the same bloom characteristics.
The Shrub Rose classification is a broad grouping that includes many modern, resilient varieties that do not fit neatly into other categories. This group notably includes the popular English Roses, which are modern hybrids bred to recapture the strong fragrance and full, multi-petaled bloom form of Old Garden Roses. Shrub roses offer a blend of old-fashioned aesthetics with the desirable repeat-blooming trait of modern cultivars.