Saturday, May 5, 2007

Botany of Roses

The leaves of most species are 5–15 cm long, pinnate, with (3–) 5–9 (–13) leaflets and basal stipules; the leaflets usually have a serrated margin, and often a few small prickles on the underside of the stem. The vast majority of roses are deciduous, but a few (particularly in southeast Asia) are evergreen or nearly so.

The flowers of most species roses have five petals, with the exception of Rosa sericea, which often has only four. Each petal is divided into two distinct lobes and are usually white or pink, though in a few species yellow or red. Beneath the petals are five sepals (or in the case of some Rosa sericea, four). These may be long enough to be visible when viewed from above and appear as green points alternating with the rounded petals. The ovary is inferior, developing below the petals and sepals.