The genus Rubus, (especially the blackberries, which are often loosely referred to as Rubus fruticosus agg.) presents some of the most difficult taxonomic problems. This is partly due to the frequency of polyploidy; also to the frequent occurrence of hybridization; and also due to apomixis, where minor differences between plants are preserved because seedlings are genetically identical to their parent. As a result, differences of opinion on the number of species to be recognized from a given region can vary tremendously (for example, a treatment by M. L. Fernald[
] in 1950 recognized 205 species for the northern half of the eastern United States plus parts of southeastern Canada, whilst H. A. Gleason and A. Cronquist in 1991 recognized only 25)[
]. Where possible, a relatively conservative approach is taken here[
Rubus bullatifolius Merr.
Rubus fimbriifer Focke
Rubus hainanensis Focke
Rubus monguillonii H.LÃ©v. & Vaniot
Rubus multibracteatus demangei H.LÃ©v.
Rubus roridus Lindl.
Common Name: Giant Bramble
Rubus alceifolius is a shrub producing each year a cluster of arching or climbing biennial stems 5 metres or more long from a woody rootstock[
]. New roots are formed where each of the stems arch and touch the ground, these develop into a new plant and can soon produce a dense, impassable thicket of growth. The stems are usually covered with rather many stout prickles[
]. The stems only produce leaves, and do not flower, in their first year of growth, forming flowering branches in their second year and then dying after fruiting
The fruits and young shoots are sometimes gathered from the wild for local use as a food. The roots are medicinal.
Rubus alceifolius is a robust, aggressive perennial scrambling shrub, spreading by long arching spiny stems, rooting at their tips, as well as by bird-dispersed seeds. It can develop dense impenetrable thickets. It is native to tropical southeast Asia but has been introduced to a number of other territories, most notably the Indian Ocean island of La RÃ©union, where it is one of the eight most threatening plant invaders to become established on the island and occurs not only on sites disturbed by people but also in primary forest with minimal disturbance. It can behave as a liana, climbing into the canopy of forest trees and increasing the risk of wind damage. It has been classified it as highly invasive in the tropics. In a joint project between USDA and the Weed Science Society of America it was identified among the highest-ranked potential future invasive weeds in USA[
E. Asia - China, Vietnam, Cambodia, Laos, Thailand, Myanmar, Indonesia.
In light places like forest edges, roadsides, secondary forest, thickets, and riverbanks, sometimes descending to sea level, but more commonly found at elevations from 500 - 1,400 metres[
In the north of its range, Rubus alceifolius grows in the warm temperate zone of central southern China (hardiness zone 8), where winters are mild but the plant experiences frosts. It is being grown outdoors in southern England (hardiness zone 7 - 8), where it is fruiting.
Grows best in a sunny position, though older plants can tolerate considerable shade[
]. Succeeds in a wide range of soils, preferring one that is well-drained[
Fruit - raw or cooked[
]. Used to make jam[
]. The aggregate, subglobose, red fruit is up to 18mm in diameter[
The roots are astringent. They are boiled and used in the treatment of dysentery[
The roots and leaves are used medicinally[
The plant has been used in traditional medicine in La RÃ©union for the treatment of fever and inflammation[
Alkaloids extracted from the roots may act to protect the liver[
]. The extracts have exhibited high activity on the breast cancer tsFT210 cell line[
Most, if not all, thicket-forming species of Rubus have good erosion control value. They usually grow satisfactorily on barren and infertile soils and invade and occupy eroded areas. They also establish quickly on burns, old fields, and logged areas. Forming extensive and nearly impenetrable thickets, they can provide excellent cover for wildlife as well as nesting sites for small birds. They are often natural pioneer species, paving the way for woodlands to develop, but they should only really be used within their native range in order to avoid any risks of them invading other habitats[
Seed - requires stratification and is best sown in early autumn in a cold frame. Stored seed requires one month stratification at about 3Â°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, mid summer in a frame[
Tip layering in July. Plant out in autumn.
Division in early spring or just before leaf-fall in the autumn[