As mentioned above under Rubus argutus, although R. argutus is currently the most widespread introduced species of Rubus in Hawaii, 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 Hawaii 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 Hawaii Volcanoes National Park at approximately 4,000 ft. elevation on the island of Hawaii. 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 Hawaii Volcanoes National Park, at about 4,000 ft. elevation on the island of Hawaii.
At present, no exploration by scientists from Hawaii 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 Hawaii. 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.