Multiflora Rose: Accurate Identification

- Multiflora rose is an invasive shrub introduced into the United States from East Asia in the mid 1800s.

It was originally used as rootstock for ornamental roses and widely planted for living fences, erosion control and to provide food and cover for wildlife.

Multiflora rose is listed as a class B noxious weed by the state of Pennsylvania.

A designation which prohibits its sale and acknowledges a widespread infestation that cannot feasibly be eradicated.

Like other plants with attractive flowers, Multiflora rose persist in our landscape partly due to an unwillingness to remove plants perceived as having a static value or value to pollinators and other wildlife.

Contrary to that belief, the dense thickets created by multiflora rose displaced native plant communities reducing plants and wildlife diversity.

Multiflora rose has pinnately compound leaves, meaning they have a central stem in which leaflets are attached.

Each leaf has between five and nine leaflets and a uniquely fringe base, or stipule, where it connects to the stem.

At one to two inches long, each leaflet is football shaped and noticeably toothed or serrated along the edges.

The leaves are usually green, but new growth and the stipules can be spotted with pink or red.

While very similar in appearance to other native and exotic rose species, multiflora rose is unique and having fringe stipules at the base of the leaf.

The stems or canes are vibrant olive green year round making them easy to distinguish from native roses, raspberries and blackberries.

Each cane is round and bears characteristic rose thorns or prickles.

From May to June, clusters of showy fragrant blossoms emerge along the canes.

Flowers are five petaled, white or pale pink and a bright yellow pollen.

In mid-summer, the fruit called rosehips replaced the flowers and persist through winter often into the next growing season.

They are one quarter inch in diameter shiny and initially a showy red, but darken over time.

This shrub thrives on poor growing sites.

It prefers full sun to moderate shade and has often found an abandoned fields, heads rows and along forest edges in roadsides.

They can also survive in the deep shade of a mature forest.

While it tolerate most sites, regardless of light moisture, salinity, or pH, it is not tolerant of extreme cold and will die below negative 28 degrees Fahrenheit.

Multiflora rose reproduces by seed, root sprouts and a vegetative process called layering.

Layering occurs when a cane comes in contact with the soil, produces roots and becomes functionally independent from the parent plant.

The fruit is available to birds nearly year round as last year's fruits are commonly found alongside this year's flowers.

Once deposited in a new location via bird droppings the seeds can persist and remain viable in the soil for up to 20 years, often germinating when the site is disturbed.

Multiflora rose can be easily confused with native roses such as pasture rose, swamp rose, and Virginia rose.

However, all native roses have pink flowers and smooth or entire stipules.

Native black raspberry and Allegheny Blackberry, both native to Pennsylvania, have compound leaves, thorns, similar growth habits and a tendency to form thickets but usually have red or purplish canes rather than the consistent olive green of multiflora rose.

And the fruit is much different from a rose.

Another exotic invasive cane farming shrub which could be mistaken for roses wine Berry but its canes are thickly covered in pink hairs rather than prickles or thorns.

Control a multiflora rose requires the ability to positively identify it from other flora and native lookalikes.

Despite its ornamental value and falsely reported wildlife benefits, this aggressive invasive plant needs to be controlled to prevent it from taking over natural areas and displacing native plants.