A rose is a perennial flowering shrub or vine of the genus Rosa, within the family rosaceae, that contains over 100 species. The species form a group of erect shrubs, and climbing or trailing plants, with stems that are often armed with sharp thorns. Most are native to Asia, with smaller numbers of species native to Europe, North America, and northwest Africa. Natives, cultivars and hybrids are all widely grown for their beauty and fragrance. [1]
The leaves are alternate and pinnately compound, with sharply toothed oval shaped leaflets. The plants fleshy edible fruit is called a rose hip. Plants range in size from tiny miniature roses to climbers that can reach 20 metres. Species from different parts of the world easily hybridize, giving rise to the many types of garden roses.
The name originates from Latin rosa, borrowed through Oscan from colonial Greek in southern Italy: rhodon (Aeolic form: wrodon), from Aramaic wurrdā, from Assyrian wurtinnu, from Old Iranian *warda (cf. Armenian vard, Avestan warda, Sogdian ward, Parthian wâr).[2][3]
Attar of rose is the steam-extracted essential oil from rose flowers that has been used in perfumes for centuries. Rose water, made from the rose oil, is widely used in Asian and Middle Eastern cuisine. Rose hips are sometimes made into jam, jelly and marmalade or brewed for tea, mainly for their vitamin C content. They are also pressed and filtered to make rose hip syrup. Rose hips are also used to produce an oil used in skin products.
Botany
Rosa canina hipsThe leaves of most species are 5–15 centimetres 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 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. The ovary is inferior, developing below the petals and sepals.
The aggregate fruit of the rose is a berry-like structure called a rose hip. Rose species that produce open-faced flowers are attractive to pollinating bees and other insects, thus more apt to produce hips. Many of the domestic cultivars 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.
Species
Further information: List of Rosa species
Rosa multifloraSome representative rose species
Pests and diseases
Main articles: Pests and diseases of roses and List of rose diseases
Roses are subject to several diseases. The most serious is rose rust (Phragmidium mucronatum), a species of rust fungus, which can defoliate the plant. More common, though less debilitating, are rose black spot, caused by the fungus Diplocarpon rosae, which makes circular black spots on the leaves in summer, and powdery mildew, caused by Sphaerotheca pannosa. Fungal diseases are best solved by a preventative fungicidal spray program rather than by trying to cure an infection after it is visible. After the disease is visible, its spread can be minimized through pruning and use of fungicides although actual infection cannot be reversed. Some rose varieties are considerably less susceptible than others to fungal disease.
The main insect pest affecting roses is the aphid (greenfly), which sucks the sap and weakens the plant. Ladybirds are a predator of aphids and should be encouraged in the rose garden. Spraying with insecticide is often recommended but should be done with care to minimize loss of beneficial insects. Roses are also used as food plants by the larvae of some Lepidoptera (butterfly and moth) species; see list of Lepidoptera that feed on roses.
Cultivation
Rose-picking in the Rose Valley near the town of Kazanlak in Bulgaria, 1870s, engraving by Austro-Hungarian traveller F. KanitzSee also: Rose cultivars named after celebrities
Roses are one of the most popular garden shrubs, as well as the most popular and commonly sold florists' flowers. In addition to their great economic importance as a florists crop, roses are also of great value to the perfume industry.
Many thousands of rose hybrids and cultivars have been bred and selected for garden use, mostly double-flowered with many or all of the stamens mutated into additional petals. 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. Twentieth-century rose breeders generally emphasized size and color, producing large, attractive blooms with little or no scent. Many wild and "old-fashioned" roses, by contrast, have a strong sweet scent.
Roses thrive in temperate climates, though certain species and cultivars can flourish in sub-tropical and even tropical climates, especially when grafted onto appropriate rootstock.
There is no single system of classification for garden roses. In general, however, roses are placed in one of three main groups:
Wild Roses
The wild roses includes the species listed above and some of their hybrids.
Old Garden Roses
Most Old Garden Roses are classified into one of the following groups. In general, Old Garden Roses of European or Mediterranean origin are once-blooming shrubs, with notably fragrant, double-flowered blooms primarily in shades of white, pink and red. The shrubs' foliage tends to be highly disease-resistant, and they generally bloom only on two-year-old canes.
Alba
Rosa x alba 'Alba Semiplena', an Alba rose
Rosa 'Maiden's Blush', an Alba roseLiterally "white roses", derived from R. arvensis and the closely allied R. alba. These are some of the oldest garden roses, probably brought to Great Britain by the Romans. The shrubs flower once yearly in the spring with blossoms of white or pale pink. The shrubs frequently feature gray-green foliage and a climbing habit of growth . Examples: 'Alba Semiplena', 'White Rose of York'.
Modern Garden Roses
A modern garden rose at University of the Pacific (United States).
Rosa 'Cajun Sunrise', a modern Hybrid Tea roseClassification of modern roses can be quite confusing because many modern roses have old garden roses in their ancestry and their form varies so much. The classifications tend to be by growth and flowering characteristics, such as "large-flowered shrub", "recurrent, large-flowered shrub", "cluster-flowered", "rambler recurrent", or "ground-cover non-recurrent". The following includes the most notable and popular classifications of Modern Garden Roses:
Landscape Roses
These are a modern classifation of rose developed mainly for mass amenity planting. In the late 20th century, traditional hybrid tea and floribunda rose varieties fell out of favor amid gardeners and landscapers, as they are often labor- and chemical-intensive plants susceptible to myriad pest and disease problems. So-called "landscape" roses have thus been developed to fill the consumer desire for a garden rose that offers color, form and fragrance, but is also low maintenance and easy to care for. Most landscape roses having the following characteristics:
Good disease resistance
Lower growing habit, usually under 60cm
Repeat flowering
Disease and pest resistance
Non suckering, growing on their own roots.
Principal parties involved in the breeding of new Landscape Roses varieties are Werner Noak (Germany) Meidiland Roses (France) Boot&Co. (Netherlands)
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