Appearance
Rubus phoenicolasius is a multi-stemmed, spiny, small shrub that invades open areas throughout the eastern United States. The canes have small spines and the entire plant is covered in minute, glandular, reddish hairs. Canes can, under favorable conditions, grow to 9 ft. (2.7 m) in length.

Foliage
The alternate leaves are compound with three heart-shaped, toothed leaflets. The undersides of the leaflets are silvery-white and very hairy.

Flowers
Small, white, 5-petaled flowers develop in May-June. The sepals are hairy and longer than the petals, giving the flowers an unopened look.

Fruit
The fruit (clusters of drupelets) are juicy and bright, shiny red in color. They are about 0.4 in. (1 cm) thick and may have fine hairs. They ripen in June to July.

Ecological Threat
Rubus phoenicolasius invades moist, open areas such as fields, roadsides, forest margins, open forests, and prairies. It reproduces by seed (which are readily dispersed by animals) and root nodes. New plants can grow from the canes touching the ground. It can form extensive, dense thickets that displace native vegetation and restrict light to the ground cover in open areas. Rubus phoenicolasius is native to eastern Asia and was first introduced into the United States in 1890 as breeding stock for new raspberry cultivars.

Resources

• Weeds Gone Wild: Alien Plant Invaders of Natural Areas - Plant Conservation Alliance
• Weed of the Week - USDA Forest Service
• Plant Invaders of Mid-Atlantic Natural Areas - National Park Service and U.S. Fish and Wildlife Service

Selected Images

Maps

Invasive Listing Sources

• Commonwealth of Pennsylvania, Department of Conservation and Natural Resources, 1994.
• Connecticut Invasive Plant List
• Connecticut Invasive Plant Working Group
• Delaware Invasive Species Council
• Delaware Invasive Species Council Invasive Species List
• Georgia Exotic Pest Plant Council - Category 4
• Indiana Invasive Species Council - Invasive Plant List
• Invasive Plant Species of West Virginia
• Jil M. Swearingen, Survey of invasive plants occurring on National Park Service lands, 2000-2007
• John Randall, The Nature Conservancy, Survey of TNC Preserves, 1995.
• Kentucky Exotic Pest Plant Council - Significant Threat
• Maine Invasive Plants
• Maryland Department of Natural Resources Policy: Restriction on Planting Exotic Invasive Plants
• Maryland Invasive Species Council - Invasive Species of Concern in Maryland
• Massachusetts Invasive Plants Advisory Group List
• Massachusetts Noxious Weeds
• Massachusetts Prohibited Plant List
• National Park Service, Mid-Atlantic Exotic Plant Management Team Invasive Plant List
• New Jersey Invasive Species Strike Team 2017 Invasive Species List
• New York Regulated and Prohibited Invasive Species - Prohibited
• Non-Native Invasive Plants of Arlington County, Virginia
• Non-Native Invasive Plants of the City of Alexandria, Virginia
• Nonnative Invasive Species in Southern Forest and Grassland Ecosystems
• Ohio Invasive Species Council
• Pennsylvania Department of Conservation and Natural Resources Invasive Plants
• Plant Invaders of Mid-Atlantic Natural Areas
• Reichard, Sarah. 1994.  Assessing the potential of invasiveness in woody plants introduced in North America. University of Washington Ph.D. dissertation.
• Rhode Island Natural History Survey
• South Carolina Invasive Pest Council
• Tennessee Exotic Pest Plant Council
• Virginia Invasive Plant Species List
• WeedUS - Database of Plants Invading Natural Areas in the United States
• West Virginia Invasive Species Strategic Plan and Volunteer Guidelines 2014
• West Virginia Native Plant Society, Flora West Virginia Project, and West Virginia Curatorial Database System, September 3, 1999
• Wisconsin Noxious Weeds
• Wisconsin's Invasive species rule – NR 40

References