The genus Rosa

The genus Rosa is subdivided into four subgenera:

Hulthemia (formerly Simplicifoliae, meaning “with single leaves”) containing two species from southwest Asia, Rosa persica and Rosa berberifolia, which are the only roses without compound leaves or stipules.
Hesperrhodos (from the Greek for “western rose”) contains Rosa minutifolia and Rosa stellata, from North America.
Platyrhodon (from the Greek for “flaky rose”, referring to flaky bark) with one species from east Asia, Rosa roxburghii (also known as the chestnut rose).

Rosa (the type subgenus, sometimes incorrectly called Eurosa) containing all the other roses. This subgenus is subdivided into 11 sections.
Banksianae – white and yellow flowered roses from China.
Bracteatae – three species, two from China and one from India.
Caninae – pink and white flowered species from Asia, Europe and North Africa.
Carolinae – white, pink, and bright pink flowered species all from North America.

Chinensis – white, pink, yellow, red and mixed-colour roses from China and Burma.
Gallicanae – pink to crimson and striped flowered roses from western Asia and Europe.
Gymnocarpae – one species in western North America (Rosa gymnocarpa), others in east Asia.
Laevigatae – a single white flowered species from China.

Pimpinellifoliae – white, pink, bright yellow, mauve and striped roses from Asia and Europe.
Rosa (syn. sect. Cinnamomeae) – white, pink, lilac, mulberry and red roses from everywhere but North Africa.
Synstylae – white, pink, and crimson flowered roses from all areas.