Rubus armeniacus is a perennial shrub, that is native to Eurasia. Stems grow to 15 ft. (4.6 m) before arching and trail the ground for up to 40 ft. (12.2 m).
Foliage
The leaves of the prima cane (first year shoots) are 2.8-7.9 in. (0.9-2.4 cm) long and are palmately compound with 5 leaflets. In the second year, several side shoots are produced (flora canes) having smaller leaves with 3 leaflets. The leaflets are oval and toothed with thorns along the underside of the mid-rib.
Flowers
No flowers are produced in this plant’s first year of life. Flowering occurs in late spring to early summer; when white to pale pink flowers develop on the flora canes. Flowers have five petals, numerous stamens and are 0.8-1 in. (2-2.5 cm) in diameter.
Fruit
Fruits are an aggregate of drupelets that are black, when mature, and 0.5-0.8 in. (1.3-2 cm) in diameter.
Ecological Threat
As the plant grows and the stems touch the ground they root at the nodes, producing a dense thicket that shades out other plant species.