Roses and Raspberries

Winding down on the side of the road is a floral show of thorny branches with white flowers. One might tend to think that they are all blackberries and raspberries, but tucked here and there is an invasive impostor – the multiflora rose. As delicious as it may smell, this rose is no friend to our native roadsides, and learning to distinguish it from our native Rubus plants will help you be able to remove it.

Rubus occidentalis

The native Rubus genus contains a bountiful collection of edible berries: raspberries, blackberries, dewberries all have bright white flowers that turn into a fruit that is actually an aggregate of drupelets. These fruits are much loved by animals, birds, and humans alike. Raspberries and blackberries grow on stiff canes while dewberries ramble along the ground like a prickly vine.

You can distinguish raspberries from blackberries most easily when you pick the fruit. When you pick a ripe blackberry, the stem inside the fruit stays with the fruit. When you pick a raspberry, the stem stays with the plant, leaving a hollow center. You can see this on the fruits you buy in the store as well.

Blackberry fruit

The canes on blackberries and raspberries take two years to mature enough to flower and bear fruit. So if you whack them down each year on the wild edges of your property, you’ll just have thorny plants and none of the benefit.

Multiflora rose (Rosa multiflora)

Multiflora rose (Rosa multiflora) is a non-native rose that was imported sometime in the 1700-1800’s as rootstock for ornamental roses. It was recommended as a “living fence” to control livestock, a crash barrier for highways, and as a cover plant for wildlife. It is adaptable to a wide variety of conditions, from roadsides to fields, forests, and some wetlands. It develops huge thorny branches that catch onto other plants, allow it to climb and then cascade back down.

Rubus occidentalis

The tight clusters of small white flowers on the rose as well as the compound leaves might allow you to mistake it for the native raspberries and blackberries.

At a distance, you might notice that the rose grows higher than the grounded native Rubus. The native Rubus has arching, stiff canes that are often 4-5 feet tall and wide while the rose is hanging down from where it has climbed over a nearby tree, shrub or fence.

Fringed stipules on Rosa multiflora

Once you get up close, the rose is more noticeably fragrant and the compound leaves have more leaflets (5 or more). Examine where the leaf joins the stems and you’ll find distinctive fringed stipules, a sure giveaway for Rosa multiflora. The thorns are fierce, especially when dead.

If you find that you have this invasive rose on your property, please get rid of it. The growth of this plant creates dense shade, outcompeting native vegetation and reducing plant diversity. Any stated or perceived benefit to having this plant can be easily satisfied by a number of native plants which would also contribute to the local plant community in other ways as well.