Calyx

The group of tough outer petals that protect the bud before it opens. Individually these petals are called sepals.

Cane

The supportive branches of a rosebush. Canes are distinguished from stems in that they have hardened and have greater caliper.

Centifolia

A class of roses thought to have originated from a wild cross between Autumn Damask and an Alba. Also known as Cabbage Roses in Europe for their globular form, the name Centifolias literally means "one hundred petals".

China

A class of roses cultivated in China for centuries prior to their discovery by the Europeans around 1800. Of particular interest was their ability to rebloom throughout the summer, a trait not shared by European roses of the day.

Classification

The on-going effort to assign every rose into a specific compartment according to its growth habits and/or genealogy so that we may succinctly describe groups of roses. Classification will always be the subject of debate as roses at the margin of one group might also fit inside the margin of an adjacent group. There are differing models of rose classification in use throughout the world.

Climbing rose

The name given to the climbing form of a bush rose, as in Climbing Iceberg or Climbing Mister Lincoln. Roses that originate in a climbing form (as opposed to sporting from a bush form) generally do not have "Climbing" in their name, as in Altissimo or Royal Sunset. See also: Large-flowered climber.

Cluster-flowered rose

The name used in Britain and Europe to describe the roses that Americans call floribundas.

Codename (aka: Denomination):

A unique name given to a new rose by its hybridizer that will be used internationally to identify the Cultivar. Generally, the first three letters are derived from the Hybridizer's last name and are presented in capitals. As roses are often marketed under different names in different countries a unique codename will help rosarians keep things straight. FRYxotic, a 1998 AARS winner, is known as Sunset Celebration in the US and as Warm Wishes in Europe.

Cornell Formula

A fungicide mixture made of household ingredients: baking soda, vinegar, water, and vegetable oil.

Cultivar (aka: variety)

A cultivated variety selected for propagation based on specific characteristics, such as form, fragrance, color, disease resistance. Wild or species roses are not cultivars