It is hardly necessary to describe the Himalayan blackberry, as it is so widespread that most people can find an actual sample without going to any great trouble. And not just in the Pacific Northwest--it appears that it is a world traveller. It is robust, and has an excellent dispersal strategy. (Basically, it tastes good! For birds and humans both.) But it is so overwhelmingly successful that it is considered a pest by home gardners, farmers, native plant groups, and the U.S. Department of Agriculture. And illegal to import without a permit. But at this point a quarrantine would hardly matter--like many other immigrants to these shores, it is here to stay.
When I was a kid I had heard that this Luther Burbank fellow had something to do with introducing the Himalaya blackberry, but I didn't know if he had simply taken the name for some hybrid he had developed, or if the plant had really come from, say, Nepal. Much later I was somewhat confused to hear that it was deemed native to England--or was it Germany?
Recent web researches have resolved the story. It seems that Luther Burbank "discovered" this plant in the catalog of an "unidentified seed exchange in India"(1), and obtained some. It grew fast and was tasty--sounds good, eh? and one begins to wonder about modern genetically modifed (GM) crops--and so he introduced it to America in 1885 as the "Himalaya Giant". Later it was found to correspond to a blackberry in Germany; possibly it had spread to England and then via the English to India. Only it really isn't native to Germany, but is reported (2) to have been introduced there in 1835. Its true origin seems to be: Armenia!
So what is commonly called the Himalyan blackberry in North America (following Burbank) is actually a world-traveller with quite a few disguises. In many places the scientific name is still given as Rubus procerus, or even Rubus discolor. But the correct name is now Rubus armeniacus, or more particularly, Rubus armeniacus Focke. (2, 3)
1. Kathy Mendelson, Pacific Northwest Garden History.
2. Dr. A. Ceska, Botanical Electronic News, No. 230 August 25, 1999
3. Dr. K. Hummer, Oregon State University.