| • Science | • People | • Locations | • Timeline |
| Contents | ||
| Rose | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Rosa arvensis (Field Rose) | ||||||||||||||
| Scientific classification | ||||||||||||||
| ||||||||||||||
| Species | ||||||||||||||
|
About 100, see text References: U. of Illinois 2002-05-29 |
A rose is a flowering shrub of the genus Rosa and the flower of this shrub.
There are more than a hundred species of wild roses, mostly from the temperate northern hemisphere. The species form a group of generally thorny shrubs or climbers, and sometimes trailing plants, reaching 2-5 m tall, rarely reaching as high as 20 m by climbing over other plants.
The leaves are 5-15 cm long, pinnate, with (3-) 5-9 (-13) leaflets and basal stipules; the leaflets have a serrated margin, and often a few small thorns 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 have five petals, usually white or pink, in a few species yellow or red. The ovary is inferior, developing below the petals and sepals.
The fruitIn botany, a fruit is the ripened ovary, together with its seeds, of a flowering plant. In cuisine, when discussing fruit as food, the term usually refers to just those plant fruits that are sweet and fleshy, examples of which would be plum, apple, and or of the rose is a berry-like structure called a rose hipRosehips also called rose haws are the fruit of the rose plant, particularly wild roses that form at the base of the flower, typically red to orange but dark purple to black in some species. Rose hips of some species, especially Rosa canina ( Dog Rose), h. 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, and inside containing 5-25 seedThis writeup is about biological seeds; for the Buddhist metaphor, see bija. A seed is the ripened ovule of gymnosperm or angiosperm plants. The importance of the seed relative to more primitive forms of reproduction and dispersal is attested to by the sus (technically acheneAn achene is a type of simple dry fruit produced by many species of flowering plants. Achenes are monocarpellate (formed from one carpel) and indehiscent (do not open at maturity) and contain a single seed that nearly fills the pericarp (fruit layers), bus) embedded in a matrix of fine, but stiff, hairs. Rose hips of some species, especially the Dog RoseThe Dog Rose Rosa canina is a scrambling shrub-like rose species native to Europe, northwest Africa and western Asia. It has also been introduced to North America. The rose ranges in height from 1-5 m and its stems are covered with small sharp spines. Rosa canina, very rich in vitamin CSee Colleen Fitzpatrick for information about a singer called Vitamin C Vitamin C is a water- soluble vitamin used by the body for several purposes. Most animals can synthesize their own vitamin C, but some animals, including guinea pigs, humans, and othe, among the richest sources of any plant. The hips are eaten by fruit-eating birdFor other meanings of bird see bird (disambiguation). Many see text Birds are bipedal, warm-blooded, egg-laying vertebrates characterized primarily by feathers, forelimbs modified as wings, and hollow bones. There are almost 9000 known species of birds ins such as thrushes and waxwings, which then disperse the seeds in their droppings. Some birds, particularly finches, also eat the seeds.
Most roses have thorns. The thorns 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 R. pimpinellifolia though have densely packed straight spines, 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 the two species cited grow naturally on coastal sand dunes). Despite the presence of the thorns, roses are frequently heavily browsed by deer. A few species of roses only have vestigial thorns that have no points.
Roses are subject to several diseases. The most serious is rose rust (Phragmidium tuberculatum), a species of Rust fungus, which can defoliate the plant. Rather commoner, but slightly less debilitating, is rose black spot , caused by the fungus Diplocarpon rosae, which makes circular black spots on the leaves in summer.