Rubus fruticosus (European Blackberry) and its close relatives, all in the Rose (Rosaceae) family, are a widespread and well known group of over 375 species native to the temperate Northern hemisphere and South America. The plants contain polyphenol antioxidants - naturally occurring chemicals that can boost metabolic processes in mammals. The astringent blackberry root is sometimes used in herbal medicine as a treatment for diarrhea and dysentery. According to forensic evidence from the skeleton of the Iron Age Haraldskær Woman, dating ±2 500 years ago, it seems reasonable to infer that blackberries have been eaten by humans for thousands of years. The soft fruit is used in desserts, jams, seedless jellies and sometimes wine. Since the many species hybridise easily, there are numerous cultivars available for commercial and amateur cultivation in Europe and United States. In other regions across the globe, such as Australia, Chile, New Zealand and the Pacific Northwest region of North America, some blackberry species are naturalised and considered an invasive species and a serious weed.
Description: Blackberries are perennial plants which bear biennial stems. In the first year a new stem (a primocane) grows vigorously to a length of 1-3 metres. The very thorny stems arch or trail on the ground and root at the tips. The foliage is large compound palmate-shaped leaves with five to seven leaflets. During the first year the stems do not bear flowers. In the second year the stem becomes a floricane (flowering stem) producing flower buds that in turn produce much branched, very thorny flower heads. The unripe fruits are bright red, (ripening to black or purple) giving rise to the quaint expression that "blackberries are red when they are green". The flowers appear in late spring and early summer. Each flower is about 2-3 cm in diameter with five white or pale pink petals. The early flowers develop during the dormant period and typically form more drupelets than the later flowers.
Invasive Status: Declared invaders - transformers. Unmanaged mature plants form a prickly tangle of dense arching stems. The stems root from the node tip where they touch the ground. Blackberry shrubs tolerate poor soils, readily colonising wasteland, forest edges, fynbos, plantations, riverbanks and roadsides. Rubus fruticosus (European blackberry) Category 2, Rubus flagellaris (Bramble) Category 1b, NEW entry: R.niveus (Ceylon or Mysore raspberry) Category 1b, R. cuneifolius (American bramble) andhybrid R.x proteus Category 1b.
Control: Registered herbicides are available.
References: ALIEN WEEDS AND INVASIVE PLANTS: Lesley Henderson Copyright @ 2001 Agricultural Research Council. www.wikipedia.org