Rubus argutus Link, Rosaceae

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Present on Pacific Islands?  yes

Threat only at high elevations?  no

Risk assessment results:  High risk, score: 21.5 (Go to the risk assessment)

Other Latin names:  Rubus penetrans L. H. Bailey

Common name(s): [more details]

English: Florida prickly blackberry, highbush blackberry, prickly Florida blackberry

Hawaiian: ōhelo ‘ele ‘ele

Habit:  shrub

Description:  "Erect or becoming arching shrubs; stems stiff and usually erect in open areas, more or less decumbent in shaded sites, primocanes 10-30 dm long, angled, covered with stout, straight or hooked prickles up to 6 (-8) mm long, their bases usually longitudinally elongated, also sparsely pilose, lateral branches of floricanes moderately to densely pilose, prickles usually smaller.  Pimocane leaves palmately compound, leaflets (3) 5, all similarly shaped, elliptic, oblong-oblanceolate, or ovate, the terminal one usually 8-13 cm long, 3.5-5 (-8) cm wide, upper surface glabrate, lower surface usually soft pilose and midrib usually with small prickles, margins coarsely and irregularly serrate, terminal leaflet with longest petiolule usually 2-4 cm long, petiolules and petioles usually pilose and with prickles; floricane leaves similar to those of primocanes but smaller, leaflets 3 (5), the terminal one usually only 5-9 cm long.  Flowers in short, open racemes, pedicels 15-20 mm long, moderately to densely villous (hairs not glandular or sometimes some of them glandular) and with prickles; petals white, obovate, 13-20 mm long.  Fruit black at maturity, subglobose to oblong, 1.5-2 cm long, cohering to the tardily separating receptacle" (Wagner et al., 1999; pp. 1107, 1890).

Habitat/ecology:  In Hawai‘i, "an extremely serious weed naturalized in a variety of disturbed habitats, including mesic to wet forest and subalpine grassland, 200-2,300 m" (Wagner et al., 1999; p. 1107).  Forms impenetrable thickets.  "Smothers low plants and shrubs.  Blocks passage on trails"  (Motooka et al., 2003).

Propagation:  Seed, spread by birds and other animals; locally by rooting of aerial shoots where they bend over and touch the ground.

Native range:  Central and eastern United States (Wagner et al., 1999; p. 1107).

Presence:

Pacific
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
State of Hawaii Hawaiian Islands	Hawai‘i (Big) Island	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (pp. 1107-1108)
State of Hawaii Hawaiian Islands	Kaua‘i Island	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (pp. 1107-1108)
State of Hawaii Hawaiian Islands	Maui Island	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (pp. 1107-1108)
State of Hawaii Hawaiian Islands	Moloka‘i Island	introduced invasive	Hughes, Guy D'Oyly (1995) (p. 9) Voucher cited: Hughes 9 (BISH) Naturalized sporadically in wet forest from 700-1120 m elevation.
State of Hawaii Hawaiian Islands	O‘ahu Island	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (pp. 1107-1108)

Pacific Rim
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
New Zealand New Zealand	New Zealand (country)	introduced invasive	Webb, C. J./Sykes, W. R./Garnock-Jones, P. J. (1988) (p. 1124) "Wasteland, roadsides, streamsides".

Control:  The Nature Conservancy's Stewardship Abstract contains control information for R. argutus in Hawai‘i.

Physical: The aerial portions of a plant are normally destroyed by fire but the plant quickly recovers from basal and subterranean shoots. Isolated plants may be grubbed out, but any remaining roots will sprout.

Chemical:  "Sensitive to foliar applications of triclopyr and picloram; dicamba not effective.  Sensitive to metsulfuron.  Susceptible to drizzle applications of triclopyr and of glyphosate in trail work on the Nāpali coast of Kaua‘i.  Chris Zimmer and Tim Tunison at HAVO reported triclopyr amine at 0.5% of product without surfactant, sprayed to wet foliage, was effective.  Pat Bily (TNC) confirmed triclopyr amine at 0.5% of product without surfactant effective.  Bily also reported 10% triclopyr ester product in vegetable-oil based carrier applied to 2-3 inches at base of each cane very effective" (Motooka et al., 2003).

Biological: Biological control of R. argutus in Hawai‘i by Croesia zimmermani Clark (Lepidoptera: Tortricidae) has been effective in pasture and open areas but of limited effect in forests (Julien, 1992; pp. 83-84).

Additional information:  Information from the book "Weeds of Hawaii‘s Pastures and Natural Areas; An Identification and Management Guide" (Motooka et al., 2003). (PDF format).
The Nature Conservancy photos and Stewardship Abstract on R. argutus in Hawai‘i.

Additional online information about Rubus argutus is available from the Hawaiian Ecosystems at Risk project (HEAR).

Taxonomic information about Rubus argutus may be available from the Germplasm Resources Information Network (GRIN).

References:

Hughes, Guy D'Oyly. 1995. New Hawaiian plant records II. In: Evenhuis, Neal L. and Miller, Scott, E., eds. Records of the Hawaii Biological Survey for 1994. Part 2: Notes. Bishop Museum Occasional Papers. 42:1-10.

Julien, M. H. (ed.). 1992. Biological control of weeds: A world catalogue of agents and their target weeds (third edition). CAB International, Wallingford, UK. 186 pp.

Meyer, Jean-Yves. 2000. Preliminary review of the invasive plants in the Pacific islands (SPREP Member Countries). In: Sherley, G. (tech. ed.). Invasive species in the Pacific: A technical review and draft regional strategy. South Pacific Regional Environment Programme, Samoa. 190 pp.

Motooka, Philip/Castro, Luisa/Nelson, Duane/ Nagai, Guy/Ching, Lincoln. 2003. Weeds of Hawaii‘s Pastures and Natural Areas; An Identification and Management Guide. College of Tropical Agriculture and Human Resources, University of Hawaii at Manoa. 184 pp.

U.S. Dept. Agr., Agr. Res. Serv. 2007. National Genetic Resources Program. Germplasm Resources Information Network (GRIN). Online searchable database.

Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. 1999. Manual of the flowering plants of Hawaii. Revised edition. Bernice P. Bishop Museum special publication. University of Hawai‘i Press/Bishop Museum Press, Honolulu. 1919 pp. (two volumes).

Webb, C. J./Sykes, W. R./Garnock-Jones, P. J. 1988. Flora of New Zealand, Volume IV: Naturalised pteridophytes, gymnosperms, dicotyledons. Botany Division, DSIR, Christchurch. 1365 pp.