Rubus alceifolius Poir., Rosaceae

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Present on Pacific Islands?  no

Primarily a threat at high elevations?  no

Risk assessment results:  Reject, score: 11 (Go to the risk assessment)

Common name(s): [more details]

Chinese: cu ye xuan gou zi

English: giant bramble

French: framboise-laine, framboisier de Java, piquant loulou, raisin marron, rou'i, vigne marronne, z'épine

Habit:  shrub

Description:  "A coarse, vigorous scrambling shrub with a woody rootstock, covering other plants and forming thickets, which reproduces by seed and layering.  Stems:  Robust, thick primary canes to 5 m long, covered with a felt of dense brown hairs and scattered hooked prickles; erect at first then arching and scrambling over other plants; short secondary canes producing flowers develop in the leaf axils of primary canes in the second growth season.  Leaves green above, velvety brown below due to a dense covering of reddish hairs; alternate, simple, to 12.5 cm across, deeply notched at the base, with 5 to 7 shallow but finely serrated lobes.  Flowers white, 1.5 to 2 cm diameter, in clusters at ends of short secondary canes, subtended by brown finely divided bracts; calyx covered at the base with brown velvety hairs.  Fruit a succulent aggregate "berry" of edible 1-seeded segments or drupelets, red when ripe.  Seed black, small, subglobular.  Root: A short woody rootstock giving rise to a sparsely branched main root with a number of fibrous laterals in the upper soil layers" (Parsons and Cuthbertson, 1992; pp. 575-577).

Habitat/ecology:  "In its native range, it grows mainly in forest openings, along paths and rivers and in disturbed areas from low to high altitudes (essentially between 300 and 1,400 m asl).  In dense primary forest, it generally grows after fire"  (Kueffer & Lavergne, 2004; p19).  "Wet gullies, creekbanks and the perimeter of rainforests in the humid tropics..."  (Parsons and Cuthbertson, 1992; pp. 575-577).  Forms impenetrable thickets.

Propagation:  Seed spread by frugivorous birds. Locally by layering and rooting tips.  "Below 1,100 m asl, R. alceifolius can spread by sexual reproduction (generating a large seed bank) and vegetative multiplication, while about 1,100 m it spreads by vegetative means only"  (Kueffer & Lavergne, 2004; p19).

Native range:  Southeast Asia.

Presence:

Pacific Rim
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
Australia Australia (continental)	Queensland	introduced invasive	Parsons, W. T./Cuthbertson, E. G. (1992) (pp. 575-577)
Cambodia Cambodia	Cambodia (Kingdom of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
China China	China (People's Republic of)	native	Zhengyi, Wu/Raven, Peter H./Deyuan, Hong (2013) "Sunny slopes, mixed forests in valleys, boggy thickets, roadsides, rock crevices; 500-2000 m".
China China	Hong Kong	native	Wu, Te-lin (2001) (pp. 127-128)
Indonesia Indonesia	Indonesia (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
Taiwan Taiwan Island	Taiwan Island	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
Thailand Thailand	Thailand (Kingdom of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
Vietnam Vietnam	Vietnam (Socialist Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)

Indian Ocean
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
La Réunion (France) La Réunion Island	La Réunion Island	introduced invasive	MacDonald, I. A. W./Thebaud, C./Strahm, W. A./Strasberg, D. (1991) (pp. 51-61)
La Réunion (France) La Réunion Island	La Réunion Island	introduced invasive	Lavergne, Christophe (2006) "Très envahissant"
La Réunion (France) La Réunion Island	La Réunion Island	introduced invasive	Kueffer, C./Lavergne, C. (2004) (p. 4)
La Réunion (France) La Réunion Island	La Réunion Island	introduced invasive	Baret, Stephane/Rouget, Mathieu/Richardson, David M./Lavergne, Christophe/Egoh, Benis/Dupont, Joel/Strasberg, Dominique (2006) (p. 758)
Mauritius Mautitius Islands (Mauritius and Rodrigues)	Mauritius Island	introduced invasive	Kueffer, C./Mauremootoo, J. (2004) (p. 6)
French Territory of Mayotte Mayotte Islands	Mayotte Island	introduced invasive	Vos, P. (2004) (p. 7)

Comments:  Invasive in La Réunion.

Control: 

Physical:  An efficient control method without negative impacts...is to cut the stems with a machete and then remove the root stumps of all the plants.  The plant material is piled up and sometimes disposed of by burning.  Mechanical removal and burning takes between 120 and 150 person-days per hectare, while mechanical removal alone takes between 60 and 80 person-days per hectare.  Recently, trials were begun to evaluate chaffing the uprooted and cut plant material with a machine.  Cutting the stems without removing the plant material proved to be ineffective"  (Kueffer & Lavergne, 2004; p. 21).

Chemical: "Apply imazapyr or triclopyr as an overall spray during the early flowering period, making sure that the plants are thoroughly wetted.  Leave the treated canes for at least 6 months and then burn.  Spray any regrowth..."  (Parsons and Cuthbertson, 1992; pp. 575-577).

Biological:  A biological control research program in R‚union screened three plant pathogens and 38 insect species.  The rust fungus Hamaspora acutissima seemed promising but it turned out to be too specific to Asian Rubus species and was not effective against the Rubus alceifolius from R‚union.  Four promising insect species progressed through biological studies and host specificity tests and from these, the argid sawfly Cibdela janthiana has been selected as a potential biological control agent.  At present, studies are focused on complementary tests in quarantine in R‚union"  (Kueffer & Lavergne, 2004; p. 21).