Information about wild roses

Description

There are more than a hundred species of wild roses, all from the northern hemisphere and mostly from temperate regions. 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 of most species 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.

Rosa canina hips (click image to se enlarged view).

The fruit of the rose is a berry-like structure called a rose hip. 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 seeds (technically 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.

Most roses have thorns or prickles. 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. Roses are also used as food plants by the larvae of some Lepidoptera species including Common Marbled Carpet.

The name originates from Persian *vrda- via Greek rhodon "rose" (Aeolic wrodon).

source  From Wikipedia, the free encyclopedia.