Olea europaea L., Oleaceae

Click on an image for links to BIGGER PICTURES

Present on Pacific Islands?  yes

Primarily a threat at high elevations?  no

Risk assessment results: 

Evaluate, score: 2 (Go to the risk assessment (Australia))
ssp. cuspidata: High risk, score: 11 (Go to the risk assessment (Pacific))
ssp. europaea: Evaluate, score: 3 (Go to the risk assessment (Pacific))

Common name(s): [more details]

Chinese: mu xi lan

English: olive

Hawaiian: ‘oliwa, ‘oliwa haole

Spanish: oliva

Tahitian: orive

Habit:  tree

Description:  "Trees to 8-10 m tall with a broad crown, sometimes shrubby; young branches grayish lepidote. Leaves narrowly elliptic to oblong or lanceolate, (1-) 2-8 cm long, (0.3-) 0.5-1.5 (-2) cm wide, upper surface glabrous, lower surface moderately to densely grayish, green, or golden lepidote.  Flowers in axillary, decussate panicles shorter than the leaves; corolla white, ca. 3.5-4 mm long. Drupes green when immature, becoming black or brownish at maturity, subglobose to narrowly ellipsoid, 6-19 mm long." 

Subspecies europaea:  "Lower leaf surface densely grayish lepidote and thick, fleshy fruit 15-19 mm long".

Subspecies cuspidata:  "Lower leaf surface moderately to densely green or golden lepidote and thinly fleshy fruit ca. 6-7 mm long" (Wagner et al., 1999; p. 992).

Habitat/ecology:  "Grass- and woodland, riparian habitats.  Where native, this tree grows in woods, scrub, and dry rocky places up to 3000 m elevation.  The growth form ranges from stunted shrubs to tall trees.  The domestic olive is a group of more than 2500 cultivars.  Naturalized plants belon to var. africana.  Where invasive, the tree forms a dense and permanent canopy under which native shrubs and trees cannot grow, but seedlings of this tree grow well.  Over time, it transforms native vegetation into a species-poor shrubland"  (Weber, 2003; p. 287).  "Growth is most prolific in semi-arid to sub-humid warm-temperate regions, usually with winter-dominant rainfall and hot, relatively dry summers, on a range of soils (Parsons & Cuthbertson, 1992, cited in Csurhes & Edwards, 1998; p. 120).  "Forms dense canopies that shade out the understory"  (Motooka et al., 2003).

Propagation:  Seed, spread by birds and animals. A prolific seed producer.

Native range:  Mediterranean region, widely cultivated.

Presence:

Pacific
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
Australia (Pacific offshore islands) Lord Howe Island	Lord Howe Island	introduced	Pickard, J. (1984) (p. 207) subsp. africana
Australia (Pacific offshore islands) Norfolk Islands	Norfolk Island		Ziesing, P. (1997) (pp. 24-25)
Australia (Pacific offshore islands) Norfolk Islands	Norfolk Island	introduced invasive	Orchard, Anthony E., ed. (1994) (p. 10) Subsp. cuspidata (Wall. ex G.Don) Cif. "Naturalised and invasive in the National Park and other areas of native vegetation". Vouchers cited: R.D. Hoogland 6635 (CANB); R.D. Hoogland 11328 (CANB, NSW); G. Uhe 1151 (K); G. Uhe 1190 (K); 1964, P. Ralston (K)
Chile (offshore islands) Juan Fernández Islands	Isla Más a Tierra (Robinson Crusoe Island)	introduced invasive cultivated	Atkinson, Rachel/Sawyer, John (2011)
Chile (offshore islands) Juan Fernández Islands	Isla Más a Tierra (Robinson Crusoe Island)	introduced cultivated	Danton, Philippe/Perrier, Christophe/Martinez Reyes, Guido (2006) (p. 555)
Ecuador (Galápagos Islands) Isabela Group	Isabela Island	introduced cultivated	Charles Darwin Foundation (2008)
Ecuador (Galápagos Islands) Isabela Group	Volcán Sierra Negra, Isabela Island	introduced cultivated	Charles Darwin Foundation (2008)
French Polynesia Marquesas Islands	Ua Huka (Huahuna, Uahuka) Island	introduced cultivated	Lorence, David H./Wagner, Warren L. (2008)
French Polynesia Marquesas Islands	Ua Huka (Huahuna, Uahuka) Island		National Tropical Botanical Garden (U.S.A. Hawaii. Kalaheo.) (2003) (voucher ID: PTBG 40851) Taxon name on voucher: Olea europaea subsp. europaea
French Polynesia Society Islands	Tahiti Island	introduced cultivated	Grant, Martin Lawrence;Fosberg, F. Raymond/Smith, Howard M. (1974) (p. 29) Voucher cited: Grant 4357 (BISH, MIN)
French Polynesia Society Islands	Tahiti Island	introduced cultivated	Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. (2011) Cultivée
French Polynesia Austral (Tubuai) Islands	Raivavae (Raevavae) Island	introduced cultivated	Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. (2011) Voucher cited: J. Florence 5724 (PAP) Cultivée
French Polynesia Austral (Tubuai) Islands	Raivavae (Raevavae) Island		Bishop Museum (Honolulu) (1983) (voucher ID: BISH 553662) Taxon name on voucher: Olea europaea L.
Guam Guam Island	Guam Island	introduced	Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1979) (p. 209)
State of Hawaii Hawaiian Islands	Hawai‘i (Big) Island	introduced invasive cultivated	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (pp. 992-994)
State of Hawaii Hawaiian Islands	Kaua‘i Island	introduced invasive cultivated	Lorence, David H./Flynn, Timothy W./Wagner, Warren L. (1995) (p. 42) subsp. africana; vouchers cited: D. Lorence & T. Flynn 7604 (PTBG), T. Flynn & Kawakami 3536 (BISH, PTBG) Abundantly naturalized.
State of Hawaii Hawaiian Islands	Lāna‘i Island	introduced invasive cultivated	Starr, Forest/Starr, Kim/Loope, Lloyd L. (2010) (p. 65) Voucher cited: Starr & Starr 070403-03 (BISH)
State of Hawaii Hawaiian Islands	Maui Island	introduced invasive cultivated	Starr, Forest/Martz, Kim/Loope, Lloyd L. (1999) (p. 13) East Maui. Subsp. cuspidata, voucher cited: Starr & Martz 971114-2 (BISH); subsp. europaea, voucher cited: Starr & Martz 980817-1 (BISH)
State of Hawaii Hawaiian Islands	O‘ahu Island	introduced invasive cultivated	Frohlich, Danielle/Lau, Alex (2010) (p. 12) Voucher cited: K. Kawelo USARMY 92 (BISH)
New Caledonia New Caledonia Archipelago	Île Grande Terre	introduced cultivated	MacKee, H. S. (1994) (p. 108) Vouchers cited: Hürlimann 190, MacKee 20617, MacKee 43735
New Zealand (offshore islands) Kermadec Islands	Raoul Island	introduced invasive	Sykes, W. R. (1977) (p. 122) Olea africana Mill.
New Zealand (offshore islands) Kermadec Islands	Raoul Island	introduced invasive	Sykes, W. R./West, C. J. (1996) (p. 456) Subject of eradication program.
New Zealand (offshore islands) Kermadec Islands	Raoul Island	introduced invasive	Webb, C. J./Sykes, W. R./Garnock-Jones, P. J. (1988) (p. 881) "confined to the Terraces". Subject of eradication program. "At present there are no mature plants on Raoul".
Tonga Vava‘u Group	Vava‘u Island	introduced cultivated	Space, James C./Flynn, Tim (2001) (p. 67) Cultivated in botanical garden.
United States (other Pacific offshore islands) Midway Atoll	Sand Island	introduced cultivated	Starr, Forest/Starr, Kim/Loope, Lloyd (2008) (pp. B-11) subsp. cuspidata

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)	Australia (continental)	introduced	U.S. Dept. Agr., Agr. Res. Serv. (2011)
Australia Australia (continental)	New South Wales	introduced invasive cultivated	Csurhes, S./Edwards, R. (1998) (p. 120) Also South Australia, Victoria and Western Australia.
Australia Australia (continental)	Queensland	introduced invasive cultivated	Csurhes, S./Edwards, R. (1998) (p. 120)
China China	China (People's Republic of)	introduced cultivated	Zhengyi, Wu/Raven, Peter H./Deyuan, Hong (2011)
New Zealand New Zealand	New Zealand (country)	introduced invasive	Owen, S. J. (1997)
New Zealand New Zealand	New Zealand (country)	introduced invasive cultivated	Webb, C. J./Sykes, W. R./Garnock-Jones, P. J. (1988) (p. 881) "Open coastal scrub and modified areas near indigenous forest margins".
Singapore Singapore	Singapore (Republic of)	introduced cultivated	Chong, Kwek Yan/Tan, Hugh T. W./Corlett, Richard T. (2009) (p. 64) Cultivated only
Taiwan Taiwan	Taiwan Island	introduced cultivated	Zhengyi, Wu/Raven, Peter H./Deyuan, Hong (2011)

Comments:  Noxious weed in South Australia.

"Norfolk Island was settled by Europeans in 1788 and soon after the African Olive (Olea europaea subsp. cuspidata) was introduced as a fence post timber. This sub-species is a vigorous growing tree with small fruit (about 1cm long). The abundant fruit is not used domestically or commercially." As the Norfolk Island native forest was cleared, the African olive became a major weed and quickly established dense closed monoculture forests. The climate suits the sub-species very well and most of the abundant seed crop germinates.

"In 1984, some 120 ha of the Norfolk Island National Park was dense olive and this area was designated as a Forestry Zone, to be cleared and planted with the native Norfolk Island Pine (Araucaria heterophylla). Control of olive in the rest of the Park will remain a significant ongoing problem for the rest of the century." (Paul Stevenson, 1997)

Control:  For additional control information see the information sheet from Weedbusters New Zealand.

Physical:  "Grazing reduces new seedling volunteering" (Motooka et al., 2003).

Chemical:  "Large olive trees injured by cut-surface applications of triclopyr, glyphosate and 2,4-D, in descending order of severity, although the kill rate was low at one year after treatment. Continuous ring cut-surface applications or drilling should provide effective kill. Saplings very sensitive to basal bark application of triclopyr at 4% product in diesel oil. Mature trees have proved tolerant to soil applications of hexazinone and tebuthiuron.  Crown and root sprouting of herbicide treated trees should be expected and retreatment planned"  (Motooka et al., 2003).

Additional information:
Excerpt from the book "Weeds of Hawaii‘s Pastures and Natural Areas; An Identification and Management Guide" (Motooka et al., 2003). (PDF format).
Report on European olive (subsp. europaea) from US Geological Survey, Biological Resources Division, Haleakala Field Station, Hawaii "Plants of Hawaii" (PDF format).
Report on African olive (subsp. cuspidata) from US Geological Survey, Biological Resources Division, Haleakala Field Station, Hawaii "Plants of Hawaii" (PDF format).
Photo and additional information at the Environment Bay of Plenty, New Zealand, web site of the Bay of Plenty Regional Council.
Information from the World Agroforestry Centre's AgroForestryTree Database.
Information sheet from Weedbusters New Zealand.

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

Information about Olea europaea as a weed (worldwide references) may be available from the Global Compendium of Weeds (GCW).

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

References:

Atkinson, Rachel/Sawyer, John. 2011. Naturalized species in the Juan Fernández Archipelago, Chile. Unpublished spreadsheet.

Bishop Museum (Honolulu). 1983. Voucher specimen #BISH 553662 (Florence, J. 5724).

Charles Darwin Foundation. 2008. Database inventory of introduced plant species in the rural and urban zones of Galapagos. Charles Darwin Foundation, Galapagos, Ecuador.

Chong, Kwek Yan/Tan, Hugh T. W./Corlett, Richard T. 2009. A checklist of the total vascular plant flora of Singapore: native, naturalised and cultivated species. Raffles Museum of Biodiversity Research, National University of Singapore. 273 pp.

Csurhes, S./Edwards, R. 1998. Potential environmental weeds in Australia: Candidate species for preventative control. Canberra, Australia. Biodiversity Group, Environment Australia. 208 pp.

Danton, Philippe/Perrier, Christophe/Martinez Reyes, Guido. 2006. Nouveau catalogue de la flore vaculaire de l'archipel Juan Fernández (Chile) [Nuevo catálogo de la flora vacular del Archipélago Juan Fernández (Chile)]. Acta Bot. Gallica 153(4):399-587.

Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. 2011. Base de données botaniques Nadeaud de l'Herbier de la Polynésie Française (PAP). (online resource).

Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce. 1979. A geographical checklist of the Micronesian dicotyledonae. Micronesica 15:1-295.

Frohlich, Danielle/Lau, Alex. 2010. New plant records from O‘ahu for 2008. In: Evenhuis, Neal L. and Eldredge, Lucias G., eds. Records of the Hawaii Biological Survey for 2008. Bishop Museum Occasional Papers 107:3-18.

Grant, Martin Lawrence;Fosberg, F. Raymond/Smith, Howard M. 1974. Partial flora of the Society Islands: Ericaceae to Apocynaceae. Smithsonian Contributions to Botany 17. 85 pp.

Lorence, David H./Flynn, Timothy W./Wagner, Warren L. 1995. Contributions to the flora of Hawai‘i. III. New additions, range extensions, and rediscoveries of flowering plants. In: Evenhuis, Neal L. and Miller, Scott, E., eds. Records of the Hawaii Biological Survey for 1994. Part 1: Articles. Bishop Museum Occasional Papers. 41:19-58.

Lorence, David H./Wagner, Warren L. 2008. Flora of the Marquesas Islands. National Tropical Botanical Garden and the Smithsonian Institution. Online database.

MacKee, H. S. 1994. Catalogue des plantes introduites et cultivées en Nouvelle-Calédonie. Muséum National d'Histoire Naturelle, Paris, 164 p.

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.

Motooka, Philip/Ching, Lincoln/Nagai, Guy. 2002. Herbicidal Weed Control Methods for Pasture and Natural Areas of Hawaii. Cooperative Extension Service, College of Tropical Agriculture and Human Resources, University of Hawai‘i. CTAHR free publication WC-8.

Orchard, Anthony E., ed. 1994. Flora of Australia. Vol. 49, Oceanic islands 1. Australian Government Publishing Service, Canberra.

Owen, S. J. 1997. Ecological weeds on conservation land in New Zealand: A database. Working draft. Wellington, New Zealand. Department of Conservation.

Pickard, J. 1984. Exotic plants on Lord Howe Island: Distribution in space and time, 1853-1981. J. of Biogeography 11:181-208.

Space, James C./Flynn, Tim. 2001. Report to the Kingdom of Tonga on invasive plant species of environmental concern.  USDA Forest Service, Honolulu. 78 pp.

Starr, Forest/Martz, Kim/Loope, Lloyd L. 1999. New plant records from East Maui for 1998. In: Evenhuis, Neal L. and Eldredge, Lucius G., eds. Records of the Hawaii Biological Survey for 1998. Part 2: Notes. Bishop Museum Occasional Papers. 59:11-15.

Starr, Forest/Starr, Kim/Loope, Lloyd. 2008. Botanical survey of Midway Atoll. Prepared for: United States Fish and Wildlife Service. 27 pp. plus appendices.

Starr, Forest/Starr, Kim/Loope, Lloyd L. 2010. New plant records from the Hawaiian Archipelago. In: Evenhuis, Neal L. and Eldredge, Lucias G., eds. Records of the Hawaii Biological Survey for 2008. Bishop Museum Occasional Papers 107:61-68.

Sykes, W. R. 1977. Kermadec Islands flora: an annotated checklist. New Zealand Department of Scientific and Industrial Research Bulletin 219, Wellington. 216 pp.

Sykes, W. R./West, C. J. 1996. New records and other information on the vascular flora of the Kermadec Islands. New Zealand Journal of Botany 34:447-462.

U.S. Dept. Agr., Agr. Res. Serv. 2011. 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.

Weber, Ewald. 2003. Invasive plants of the World. CABI Publishing, CAB International, Wallingford, UK. 548 pp.

Wester, Lyndon. 1992. Origin and distribution of adventive flowering plants in Hawai‘i. In: Stone, Charles P.; Smith, Clifford W. and Tunison, J. Timothy. Alien plant invasions in native ecosystems of Hawaii: Management and Research. University of Hawaii, Cooperative National Park Research Studies Unit, Honolulu. University of Hawaii Press. .

Zhengyi, Wu/Raven, Peter H./Deyuan, Hong. 2011. Flora of China (online resource).

Ziesing, P. 1997. Norfolk Island weed control manual for selected weeds occurring in Norfolk Island National Park. Environment Australia, Norfolk Island.