• A roseis a woody perennial flowering plant of the genus Rosa, in the family Rosaceae, or the flower it bears. There are over a hundred species and thousands of cultivars. They form a group of plants that can be erect shrubs, climbing or trailing with stems that are often armed with sharp prickles. Flowers vary in size and shape and are usually large and showy, in colours ranging from white through yellows and reds. Most species are native to Asia, with smaller numbers native to Europe, North America, and northwestern Africa. Species, cultivars and hybrids are all widely grown for their beauty and often are fragrant. Roses have acquired cultural significance in many societies. Rose plants range in size from compact, miniature roses, to climbers that can reach seven meters in height. Different species hybridize easily, and this has been used in the development of the wide range of garden roses.

 

Kingdom:	Plantae
Clade:	Angiosperms
Clade:	Eudicots
Clade:	Rosids
Order:	Rosales
Family:	Rosaceae
Subfamily:	Rosoideae
Genus:	Rosa

Medicinal and other uses :

• The rose hip, usually from  canina, is used as a minor source of vitamin C.
• The fruits of many species have significant levels of vitamins and have been used as a food supplement. Many roses have been used in herbal and folk medicines.
• Rosa chinensis has long been used in Chinese traditional medicine.
• This and other species have been used for stomach problems, and are being investigated for controlling cancer growth.In pre-modern medicine, diarrhodon is a name given to various compounds in which red roses are an ingredient.

Botany

Longitudinal section through a developing rose hip

Exterior view of rose buds

Rose leaflets

Size can be as small as a thumbnail

The leaves are borne alternately on the stem. In most species they are 5 to 15 centimetres (2.0 to 5.9 in) 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. Most roses are deciduous but a few (particularly from South east Asia) are evergreen or nearly so.

The hybrid garden rose “Amber Flush”

The flowers of most species have five petals, with the exception of Rosa sericea, which usually has only four. Each petal is divided into two distinct lobes and is 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. There are multiple superior ovaries that develop into achenes.^[4] Roses are insect-pollinated in nature.

The aggregate fruit of the rose is a berry-like structure called a rose hip. Many of the domestic cultivars do not produce hips, as the flowers are so tightly petalled that they do not provide access for pollination. The hips of most species are red, but a few (e.g. Rosa pimpinellifolia) have dark purple to black hips. Each hip comprises an outer fleshy layer, the hypanthium, which contains 5–160 “seeds” (technically dry single-seeded fruits called achenes) embedded in a matrix of fine, but stiff, hairs. Rose hips of some species, especially the dog rose (Rosa canina) and rugosa rose (Rosa rugosa), are very rich in vitamin C, among the richest sources of any plant. The hips are eaten by fruit-eating birds such as thrushes and waxwings, which then disperse the seeds in their droppings. Some birds, particularly finches, also eat the seeds.

Rose thorns are actually prickles – outgrowths of the epidermis.

While the sharp objects along a rose stem are commonly called “thorns”, they are technically prickles—outgrowths of the epidermis (the outer layer of tissue of the stem). (True thorns, as produced by e.g. Citrus or Pyracantha, are modified stems, which always originate at a node and which have nodes and internodes along the length of the thorn itself.) Rose prickles are typically sickle-shaped hooks, which aid the rose in hanging onto other vegetation when growing over it. Some species such as Rosa rugosa and Rosa pimpinellifolia have densely packed straight prickles, probably an adaptation to reduce browsing by animals, but also possibly an adaptation to trap wind-blown sand and so reduce erosion and protect their roots (both of these species grow naturally on coastal sand dunes). Despite the presence of prickles, roses are frequently browsed by deer. A few species of roses have only vestigial prickles that have no points.

Species

Further information: List of Rosa species

The genus Rosa is subdivided into four subgenera:

• Hulthemia(formerly Simplicifoliae, meaning “with single leaves”) containing one or two species from southwest Asia,  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-color 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.

Rosa gallica Evêque, painted by Redouté

Uses

Roses are best known as ornamental plants grown for their flowers in the garden and sometimes indoors. They have been also used for commercial perfumery and commercial cut flower crops. Some are used as landscape plants, for hedging and for other utilitarian purposes such as game cover and slope stabilization. They also have minor medicinal uses.

Ornamental plants

Main article: Garden roses

The majority of ornamental roses are hybrids that were bred for their flowers. A few, mostly species roses are grown for attractive or scented foliage (such as Rosa glauca and Rosa rubiginosa), ornamental thorns (such as Rosa sericea) or for their showy fruit (such as Rosa moyesii).

Hybrid tea rose cultivar ‘Mrs. Herbert Stevens’

Ornamental roses have been cultivated for millennia, with the earliest known cultivation known to date from at least 500 BC in Mediterranean countries, Persia, and China. Many thousands of rose hybrids and cultivars have been bred and selected for garden use as flowering plants. Most are double-flowered with many or all of the stamens having mutated into additional petals.

In the early 19th century the Empress Josephine of France patronized the development of rose breeding at her gardens at Malmaison. As long ago as 1840 a collection numbering over one thousand different cultivars, varieties and species was possible when a rosarium was planted by Loddiges nursery for Abney Park Cemetery, an early Victorian garden cemetery and arboretum in England.