Rubus armeniacus aka Himalaya Blackberry

Rubus armeniacus has two common names: Himalayan blackberry and Armenian blackberry. It belongs to Rosaceae, the rose family. Kew gives its native range as Transcaucasus to northwestern Iran. The name does not prove that it comes from the Himalayas. This shrub has spread far beyond its native range. In parts of North America, it forms dense, invasive growth. Oregon State notes its spread across the Pacific Northwest.

Plants reach about 10 feet (3 metres) tall. Plants For A Future gives a spread of 13 feet (4 metres). Single canes can exceed 20 feet (6 metres) in one season. New canes stand upright, then bend toward the ground. Nodes, or joints, can take root when they touch soil. This growth forms dense thickets that block access. The shrub keeps all or some of its leaves through winter.

The thick canes have sharp angles and a dark purple tint. Strong, curved prickles cover the canes and can catch skin. Leaves grow along the stems in an alternate pattern. Each leaf has three to five leaflets with toothed edges. The upper sides look dark green and have some gloss. The pale lower sides bear soft hairs. First-year canes grow leaves but do not bear flowers. In the second year, side shoots bear leaves and flowers.

Flowers grow in groups, from white to pinkish red. Each flower is about one inch across. Insects pollinate the flowers. Plants are self-fertile, so they can use their own pollen. The glossy black fruit has many small parts called drupelets. Fruit reaches about one inch long and keeps its central core. People eat the sweet fruit fresh or cook it. They use it for jam, desserts, juice, and wine. Plants For A Future reports no known hazards. Even so, the prickles pose a clear risk when handling it.

This shrub grows fast in sun or light shade. It grows in sand, loam, and clay, even on poor ground. It prefers soil that drains well and stays moderately moist. Once plants take hold, they can cope with dry spells and drought. Plants For A Future lists USDA zones 5–9. Oregon State gives zone 6. It spreads along streams, roads, and fences, and into disturbed sites. Its fruit and dense growth give wildlife food and cover. It can form barriers along fences and help limit erosion. Where it invades, its fast spread can outweigh these uses.