Himalayan Blackberry - Rubus discolor
Family: Rosaceae (Rose family) [E-flora]
Description
"Rubus procerus is a deciduous Shrub growing to 10 m (32ft 10in) at a fast rate.
It is hardy to zone (UK) 5 and is not frost tender. It is in flower from Jul to August, and the seeds ripen from Aug to September. The flowers are hermaphrodite (have both male and female organs) and are pollinated by Insects.The plant is self-fertile."
"Suitable for: light (sandy), medium (loamy) and heavy (clay) soils and prefers well-drained soil. Suitable pH: acid, neutral and basic (alkaline) soils. It can grow in semi-shade (light woodland) or no shade. It prefers moist soil." [PFAF]
Himalayan blackberry is an introduced invasive species of Rubus that originates in Armenia. It was introduced to Europe in 1835, and Australasia and North America in 1885, for its fruit, but soon escaped and naturalized (Wikipedia 2010). It is now present in most of temperate regions of the world. In North America, Himalayan blackberry is found in many US states (USA (AL, AR, AZ, CA, CO, DC, DE, HI, ID, IL, KY, MA, MO, MT, NJ, NM, NV, OH, OR, PA, TN, UT, VA, WA) and two Canadian provinces (BC, ON) (USDA 2010). It appeared in BC in the 1970's and was collected by Brink and McHale in 1973 in Pitt Meadows (UBC Herbarium record, V178889). In the lower Fraser delta this species forms thick hedgerows along fields and waterways, and provides 'briar patch' shelter for feral domestic rabbits. It is an ecosystem altering species that disrupts natural systems. [E-flora]
Both its scientific name and origin have been the subject of much confusion, with much of the literature referring to it as either Rubus procerus or Rubus discolor, and often mistakenly citing its origin as western European.[2][3][4][Wiki]
- Origin Status: Exotic [E-flora]
- General: Medium to tall, coarse shrub, 2-5 m or more long, thicket-forming; stems 5-15 mm in diameter, erect to ascending, then high-arching, sprawling and trailing along the ground, some rooting at the ends, five-angled, with stout, flattened, hooked prickles.[IFBC-E-flora]
- Leaves: Alternate, evergreen, palmately compound, 5-20 cm long; leaflets 5 on first-year canes, mostly 3 on flowering canes, egg-shaped, 5-12 cm long, double-saw-toothed and abruptly sharp-pointed at the tip, green and smooth above, greyish-woolly beneath, the leaf-stalks and midveins beneath prickly; stipules linear.[IFBC-E-flora]
- Flowers: Inflorescence of 5 to 20 stalked flowers in open, terminal or axillary clusters, the stalks woolly and prickly; corollas white to pinkish, the petals 5, spreading, egg-shaped, 10-15 mm long; calyces woolly, 5-lobed, the lobes lanceolate, bent back, 8-12 mm long; ovaries superior; stamens 100 or more.[IFBC-E-flora]
- Fruits: Drupelets, smooth, coherent in a black nearly globe-shaped cluster that falls with the fleshy receptacle (a blackberry), the berries 1-1.5 cm wide.[IFBC-E-flora]
- Habitat: Moist to wet waste places, roadsides, ditches and fencerows in the lowland zone.[IFBC-E-flora]
- Range: common in SW BC; introduced from Asia.[IFBC-E-flora]
Food Uses
- Fruit - raw or cooked in pies, cakes etc[3, 105, 183]. The fruit can also be dried for later use[183]. Very large for a blackberry[50, 183] with a very pleasant rich flavour when fully ripe[K]. [PFAF]
Other Uses
- Dye: A purple to dull blue dye is obtained from the fruit[168]. [PFAF]
Cultivation
"Easily grown in a good well-drained loamy soil in sun or semi-shade[1, 11, 200]. A form of this species, known as 'Himalayan giant', is commonly cultivated in temperate zones for its edible fruit[50]. Although a blackberry, the stems are often perennial and can fruit for more than one year[50].... Plants in this genus are notably susceptible to honey fungus[200]." [PFAF]
- Control of Himalayan blackberry can be achieved by digging, mowing or herbicides. One novel approach to control is livestock grazing, particularly by goats--a method that is widely used in Australia and New Zealand to control blackberry (Cox 2003). Goats remove the top growth of the plant, eventually killing it. Research has shown that Himalayan blackberry occurs in soils that have more sand than clay present (Caplan and Yeakley 2006).[E-flora-Notes]
Propagation
"Seed - requires stratification and is best sown in early autumn in a cold frame. Stored seed requires one month stratification at about 3°c and is best sown as early as possible in the year. Prick out the seedlings when they are large enough to handle and grow on in a cold frame. Plant them out into their permanent positions in late spring of the following year. Cuttings of half-ripe wood, July/August in a frame[200]. Tip layering in July. Plant out in autumn. Division in early spring or just before leaf-fall in the autumn[200]." [PFAF]
Wildlife Habitat
Roof Rat - Himalayan Blackberry Association
"The Himalayan blackberry readily climbs, often shading out bushes and small trees 10 to 15 feet high. Without support, berry brambles commonly reach 6 to 8 feet, with occasional thickets as high as 10 feet. Such vigorously growing thickets develop layers of dead canes and leaves at a point where the supporting canes cross. As the thicket matures, the layers become thick and after a few years the materials eventually coalesce from the weight creating a single dense, thick layer. These accumulations or mid-layers of canes and leaves are used as nesting sites by roof rats. Although it is difficult to establish age of a thicket, approximately 8 years are required for layering to develop sufficiently to provide harborage for roof rats." (Dutson,1974)
"In shaded areas, canes grow sparsely within the thicket and the dead canes and leaves do not become trapped and midlayers are not formed. Therefore little or no nesting cover is available. Moreover, the open growth form exposes the roof rat population to more predation. The importance of vigorous growth form to the incidence of rat habitation was determined from surveys conducted in the Sierra Nevada foothills from January 1965 through December 1972.* Of 39 thickets surveyed by snap-trapping, 20 (51%) were positive for roof rats. The actual rate of infestation was higher, as in several instances, roof rat sign was evident or the traps were sprung. Growing conditions that support pine trees are apparently not sufficient to produce vigorous growths of Himalayan blackberry. In contrast, thickets associated with oak trees grow vigorously. Thickets growing near yellow pine (Pinus ponderosa) had a 29% infestation rate, with a trapping success of 5.8% for 315 trap nights. In areas where thickets were associated with oak (Quercus douglassi and occasionally Q. wislezenii) the infestation rate increased to 72.7% and the trapping success reached 14.5% for 398 trap nights." (Dutson,1974)
"The structure of the Himalayan blackberry thicket not only protects the roof rat from predators, but, in addition, it protects them from adverse weather. Temperature and humidity were recorded inside and outside of blackberry thickets growing at 1000 feet elevation and occurring within favorable growth conditions of the northern Sierra Nevada foothills near Auburn, California. Recordings were taken at ground level (3 inches above ground) and at 6 feet above ground both inside and outside the blackberry thickets. Winter temperatures (Figure 3) at ground level averaged 7° F warmer inside than outside the thicket between 10 p.m. December 26 and 8 a.m. December 27, 1972. During the summer (Figure 4) temperatures at the ground level averaged 16.1° F cooler inside the thicket between 4 a.m. June 6, and 6 a.m. June 7, 1973. The locations for determining temperature and humidity were the same for both winter and summer. The outside hygrothermographs were kept completely shaded without restricting air movement during the summer recording. The Himalayan blackberry thicket provides good protection during cold and hot weather, particularly if layering has developed. Relative humidity during the winter check was 100% outside the thicket under foggy conditions and 86% inside the thicket. Relative humidity during the summer averaged 61.5% inside the thicket and 43.1% outside. Utilization of this habitat may enhance retention of the rats body water during the dry summer and fall seasons." (Dutson,1974)
"An all-time record freeze occurred during December 1972, killing, to the ground, all thickets of the Himalayan blackberry and the few thickets of the evergreen blackberry (R. laciniatus) in the Shasta and Scott Valleys of Siskiyou County in northern California. The freeze lasted 12 days and included 5 days that averaged -8.6° F. These thickets sprouted vigorously during the summer of 1973, and it is estimated that they will reach previous growth and form by the end of the 1974 growing season. Roof rats either died from the cold or found shelter in nearby homes as was determined by subsequent trapping." (Dutson,1974)
- (Dutson,1974) Dutson, Val J. "The association of the roof rat (Rattus rattus) with the Himalayan Blackberry (Rubus discolor) and Algerian Ivy (Hedera canariensis) in California." Proceedings of the Vertebrate Pest Conference. Vol. 6. No. 6. 1974.
- [E-flora] Rubus armeniacus, http://linnet.geog.ubc.ca/Atlas/Atlas.aspx?sciname=Rubus%20armeniacus, [Accessed: 9/21/2014]
- [Notes]]
- Cox, Caroline. 2003. Nonchemical methods for removing unwanted blackberry plants. Journal of Pesticide Reform 23 (1): 10-11.
- Caplan, Joshua S. and J. Alan Yeakley. 2006. Rubus armeniacusOccurrence and Growth in Relation to Soil and Light Conditions in Western Oregon. Northwest Science 80 (1): 9-10.
- [Notes]]
- [PFAF] Rubus procerus, Plants for a Future, http://www.pfaf.org/user/Plant.aspx?LatinName=Rubus+procerus, Accessed Aug 20, 2016
- [Wiki] https://en.wikipedia.org/wiki/Rubus_armeniacus, Wikipedia, Accessed Aug 20, 2016
- [2]Ceska, A. (1999). Rubus armeniacus - a correct name for Himalayan Blackberries Botanical Electronic News 230. Available online.
- [3]Flora of NW Europe: Rubus armeniacus
- [4]University of British Columbia Botany Photo of the Day: July 21, 2005 : Rubus armeniacus