Wild rose plants have a loose, relaxed form and are often hardy and drought tolerant. Their flowers are generally smaller than cultivated varieties and may be highly fragrant or unscented. Some found in the wild are true natives, but others may have escaped from cultivation. Still others, like the 'Harrison's Yellow' found in western states, can be an indicator of old homesteads. Identification is based on flower size, fragrance, color, leaf characteristics and shrub height and form.
Take note of the flower color and size; petal number and shape; fragrance; and whether they are borne in sprays or singly. Most truly wild roses have flowers with only five petals, usually pink. Most also bloom only once, in early summer. Any rose blooming later in the season may be a cultivated variety gone wild.
Later in the year, look at the size and shape of the hips for clues to the species.
Leaf Shape and Texture
Rose leaves are divided into leaflets, a single stem with three or more smaller leaves branching off of it. Note whether the edges are toothed and whether the surface of the leaf is flat or ridged. One rose native to northern Asia sometimes found in the wild is Rosa rugosa, the Japanese rose. "Rugosa" refers to the rugose or corrugated textured of the leaves.
Shrub Form and Characteristics
The height of the shrub, whether the stems arch or stand stiffly straight, whether it is growing in sun or shade and whether it is densely or sparsely thorny are all details that help identify a rose. Note also the surrounding ecosystem, whether it is dry or boggy, a sandy shore or mountainside.
Common Native Roses
From Nebraska east you may encounter Rosa carolina, R. palustris, Carolina roses and swamp roses. Both are small shrubs with 2-inch pink flowers.
Rosa blanda, the prairie rose, grows from Ontario to Texas and west to the Rocky Mountains. It's a climber with light-pink flowers fading to white.
Farther west, common wild roses include R. nutkana with 1-inch-wide pink flowers and R. woodsii with white to dark rose flowers. Both make large thickets 4 to 5 feet high.
Cultivated Species Gone Wild
Rosa multiflora, an Asian species considered a noxious weed in many places, has large clusters of white flowers and can reach a height of 15 feet.
Rosa eglanteria, the eglantine rose mentioned in Shakespeare, has very small pink flowers but apple pie-scented foliage. It also makes a large shrub.
Rosa rugosa has corrugated leaves and large, purple-pink flowers that bloom throughout the summer. Its hips are also large, 1 1/2 inch across.