Himalayan Blackberry

Himalayan blackberry (Rubus ulmifolius, syn: R. discolor)

Hawaii Pacific Weed Risk Assessment: 24 High Risk

Regulatory Status: None

Prevention and Control Category: OISC Target Species

Report this species if seen on Oahu

himalayanblackberry2Description

  • Spiny, woody bramble that grows as a sprawling bush, but may reach heights of 4 m (13 ft)
  • White to pinkish flowers that become shiny black fruit when ripe
  • Native to Western Europe, introduced as an ornamental and backyard food crop

Impacts

  • Found in disturbed areas, open fields and around fresh water habitats
  • Forms dense, impenetrable thickets that exclude other native plant species
  • Seeds are spread by fruit-eating birds and mammals, also spreads vegetatively
  • Thickets also make access difficult for hunters, hikers and other visitors to forest
  • Infestations can produce 7,000-13,000 seeds per square meter, which can remain dormant in the soil for several years

himalayanblackberry3Distribution

  • Kauai: None known.
  • Oahu: Known from only two areas on Oahu: Mauumae Trail and Palolo Valley in the southeastern corner of the island. OISC is working to eradicate these populations.
  • Maui: Present at Waikamoi and Kaulalewelewe, West Maui, near the beginning of the trail to Puu Kukui.
  • Molokai: None known.
  • Lanai: Presence/absence unknown
  • Kahoolawe: None known.
  • Big Island: Present, but not currently a BIISC target. Landowners are encouraged to control where possible.

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