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.