Scientific Name: Rosa multiflora
Common Name: Multiflora Rose
(Information for this species page was gathered in part by Ms. Lisa Galbraith as part of an assignment in Biology 220W, Spring 2005)
Multiflora rose (Rosa multiflora) is an introduced plant species that is native to Japan, Korea, and Eastern China. It was first brought to the United States in the 1860’s for use as root stock for ornamental roses. It was subsequently used as a “living fence” plant, as highway buffer vegetation, and in a variety of disturbed land reclamation programs. Soon, though, the invasive and destructive potential of this plant was recognized. Most states have placed multiflora rose on the “noxious weed” or “banned invasive” lists and are both preventing its sale and planting and also actively attempting to extirpate it from areas in which has become established.
Range and Habitat
Multiflora rose can be found throughout the United States except for the Rocky Mountain region, the extreme desert southwest, and most of the state of Florida. It grows rapidly in fields, pastures, roadsides, and sun-lit edges and spaces of a forest. It is especially common in forest sun gaps that are generated by fallen trees. Its rapid growth and tendency to form dense, monocultural thickets outcompetes and over-shades most native plants.
Appearance, Pollination, Fruits and Seeds
Multiflora rose is a perennial plant that grows in long (up to 15 feet), arching, thorny stems that are called “canes.” It has compound leaves that usually are divided into 7 to 9 serratedly edged leaflets. The leaves arise alternately on the long canes. Flowers (which form in May of June) are pink or white and very fragrant. They are pollinated by a diverse array of hymenopterans. A pollinated flower will eventually form a small, leathery, red fruit around a single, hard seed. This fruit is called a “hip.” Hips may persist on the plant through the next winter and, possibly, for several years. Hips are consumed by a wide array of birds. American robins, cedar waxwings, and northern cardinals are especially fond of these rose hips. Passage of the seed through the digestive tract of a bird significantly increases the likelihood of the seed’s germination. Birds, then, represent significant symbionts for the multiflora rose by accomplishing both seed dispersal and scarification.
In addition to developing from seed, multiflora rose is also capable of rooting from the tips of its arching canes. New canes grow up and over older canes, then, and form an expanding, dense mass of heavily thorned stems. These thickets allow very little other vegetative growth within them and, thus, represent an ecological disaster for native plant species. These thickets, though, do represent a highly protective microhabitat for many small mammals (like cottontail rabbits and woodchucks) and birds (including bobwhite quail, pheasants, and many small song birds).
Multiflora rose is one of the first plants to leaf out in the early spring. This early start on photosynthesis gives the plant an energetic advantage over its many potential competitors. The shade generated by the its leaves also acts to inhibit the growth and survival of many other spring plants.
A "Good" and "Bad" Plant
On several of my “Signs of Spring” essays and blogs and on a number of my hiking narratives (on the web site “Between Stones and Trees: An Ecologist Hikes Western Pennsylvania”) I have written about multiflora rose. I have observed its extensive and expanding distribution along our hiking trails and across our river valleys and ridge tops. I have watched a massive multiflora thicket grow and develop at the bottom of a field adjacent to my home (left). Multiflora rose is a disastrous invasive species when you consider its impact on native plants. But, watching the flocks of northern cardinals, chickadees, titmice, and house finches that find rest and nest sites within it, and observing the many generations of cottontails that have found shelter and protection under its thorny canes, I feel that the whole story of multiflora rose and its impact on biological diversity and habitat quality of an ecosystem is, at best, a complex story.