All roses were originally single, composed of five petals, with the exception of a single four-petaled species. These oddities were saved and propagated by gardeners. Today, a double rose is the norm, although there are also rose cultivars with single and semi-double flowers. Petal counts among rose cultivars range from five into the hundreds. Flower form is a function of petal count and petal length.
Petal length is dependent on a rose cultivars ancestry.
The petals of Old Garden Roses are typically short and numerous. The mature flower is usually very double and when fully open is flat or cupped in appearance. The arrangement of petals sometimes gives the flower a quartered appearance, and often there is a button eye in the flower center. Sometimes, as seen among the Centifolias, the outer petals are larger and curve up and around the short, inner petals, resulting in a mature flower with a globular form. Flower buds of Old Garden Roses are not considered very attractive.