Rubus ellipticus

As mentioned above under Rubus argutus, although R. argutus is currently the most widespread introduced species of Rubus in Hawai‘i, there are several other nonnative species present, some of which show indications of becoming serious pests if their ranges are allowed to expand.  Of these Rubus ellipticus is perhaps the most threatening.  This species originates in Northern India in the foothills of the Himalayas it is also known from Southern China.  Rubus ellipticus, known in Hawai‘i as yellow Himalayan raspberry, produces stout, heavily armed arching canes in dense thickets, growing to 15 ft. tall or more.  Currently it is invading pasture land and is encroaching into forest land in the vicinity of Hawai‘i Volcanoes National Park at approximately 4,000 ft. elevation on the island of Hawai‘i.   Outlying populations have been found in the mid-elevation forests on the eastern side of that island, presumably arising from seeds carried by birds.

   Closeup of the fruit and foliage of Rubus ellipticus.

     Thickets of invading Rubus ellipticus in forest and pastureland near Hawai‘i Volcanoes National Park, at about 4,000 ft. elevation on the island of Hawai‘i.

At present, no exploration by scientists from Hawai‘i has been undertaken in search of potential biocontrol agents for R. ellipticus.  However, my research program has provided funding for such work to be conducted by local scientists in China, under a cooperative agreement with the Cooperative (National) Park Studies Unit at the University of Hawai‘i.  Efforts thus far have concentrated on assembling bibliographies of local literature on this species, and some preliminary field investigations to locate populations of the species.