- Summary of Invasiveness
- Taxonomic Tree
- Notes on Taxonomy and Nomenclature
- Plant Type
- Distribution Table
- History of Introduction and Spread
- Risk of Introduction
- Habitat List
- Biology and Ecology
- Latitude/Altitude Ranges
- Air Temperature
- Rainfall Regime
- Soil Tolerances
- Notes on Natural Enemies
- Means of Movement and Dispersal
- Impact Summary
- Impact: Biodiversity
- Threatened Species
- Risk and Impact Factors
- Uses List
- Wood Products
- Prevention and Control
- Links to Websites
- Distribution Maps
Don't need the entire report?
Generate a print friendly version containing only the sections you need.Generate report
PicturesTop of page
IdentityTop of page
Preferred Scientific Name
- Acacia confusa Merr.
International Common Names
- English: acacia petit; Formosan acacia; Formosan koa; mimosa; small Phillipine acacia; Taiwan acacia
- Chinese: Taiwan xiangshi
Local Common Names
- Guam: boiffuring; shoshigi; sosigi; sosugi
- Micronesia, Federated states of: pilampwoia
- Northern Mariana Islands: serepa; soschghi
- Palau: ianángi; yanangi
- ACACU (Acacia confusa)
- Taiwan acacia
Summary of InvasivenessTop of page A. confusa is invasive in Hawaii (Luken and Thieret, 1996). Bingelli (1999) classed this species as moderately invasive.
Taxonomic TreeTop of page
- Domain: Eukaryota
- Kingdom: Plantae
- Phylum: Spermatophyta
- Subphylum: Angiospermae
- Class: Dicotyledonae
- Order: Fabales
- Family: Fabaceae
- Subfamily: Mimosoideae
- Genus: Acacia
- Species: Acacia confusa
Notes on Taxonomy and NomenclatureTop of page A. confusa is in the tribe Acacieae of the genus Acacia.
DescriptionTop of page A. confusa is small tree with adult foliage of falcate phyllodes, juvenile and sucker-shoot of bipinnate leaves; trunk up to 1 m thick in very old trees; phyllodes alternate, coriaceous, parallel-curving-veined, 8-10 cm long, narrowed at both ends; flowers yellow, in small globose heads 6-8 mm in diameter; heads 1 or 2 in axil of phyllode; pods few together, linear or somewhat curved, flat or slightly twisted, brown, 5-10 cm long, 1 cm broad or a little more or less, with about eight seeds; seeds compressed, brown (Stone, 1970; PIER, 2002)
Plant TypeTop of page Broadleaved
DistributionTop of page A. confusa has a restricted native range, apparently native only to Taiwan and the northern Philippines.
Distribution TableTop of page
The distribution in this summary table is based on all the information available. When several references are cited, they may give conflicting information on the status. Further details may be available for individual references in the Distribution Table Details section which can be selected by going to Generate Report.
|Continent/Country/Region||Distribution||Last Reported||Origin||First Reported||Invasive||Planted||Reference||Notes|
|China||Present||Present based on regional distribution.|
|Japan||Present||Present based on regional distribution.|
|-Ryukyu Archipelago||Present||Introduced||PIER, 2002|
|Malaysia||Present||Present based on regional distribution.|
|-Peninsular Malaysia||Present||Introduced||PIER, 2002|
|Philippines||Present||Native||Luken & Thieret, 1996; PIER, 2002|
|Taiwan||Present||Native||Luken & Thieret, 1996; PIER, 2002; Wagner et al., 1999|
|USA||Present||Present based on regional distribution.|
|-Hawaii||Present||Introduced||c. 1915||Invasive||Luken & Thieret, 1996|
|Micronesia, Federated states of||Present||Introduced||PIER, 2002|
|Northern Mariana Islands||Present||Introduced||PIER, 2002|
History of Introduction and SpreadTop of page A. confusa was introduced to Hawaii, USA in 1915 and has also been introduced and planted in a number of Asian, Pacific and Indian Ocean countries, and PIER (2002) report that it continues to be actively planted in Micronesia.
Risk of IntroductionTop of page It is possible that the species may become invasive in other areas where it has been introduced. Information on the biology and management of A. confusa is not widely available, but PIER (2002) report that due to its status as a pest in some countries e.g. Hawaii, it should not be introduced to islands where it is not already present.
HabitatTop of page A. confusa is a nitrogen fixing species and a pioneer tree on wastelands, adaptable to a wide range of soils.
Habitat ListTop of page
Biology and EcologyTop of page A. confusa reproduces from seeds and from cuttings. Fire can stimulate the germination of large numbers of seeds, and it will also resprout after fire (PIER, 2002). A. confusa is a nitrogen fixing species and a pioneer tree on wastelands, growing rapidly and has great adaptability including shallow and infertile soils, though it prefers acid, free-draining soils. A. confusa prefers a summer or uniform rainfall regime, a mean annual rainfall of 1300 to 3000 mm, and a dry season duration not exceeding 5 months. The mean annual temperature in its native range is 18-26°C, with the mean minimum of the coolest month 14-16°C and the mean maximum of the hottest month 26-29°C, and it will tolerate an absolute minimum temperature of 0°C. It is generally a lowland species but can be found at altitudes up to 800 m.
Latitude/Altitude RangesTop of page
|Latitude North (°N)||Latitude South (°S)||Altitude Lower (m)||Altitude Upper (m)|
Air TemperatureTop of page
|Parameter||Lower limit||Upper limit|
|Absolute minimum temperature (ºC)||-8||0|
|Mean annual temperature (ºC)||18||26|
|Mean maximum temperature of hottest month (ºC)||26||29|
|Mean minimum temperature of coldest month (ºC)||14||16|
RainfallTop of page
|Parameter||Lower limit||Upper limit||Description|
|Dry season duration||2||5||number of consecutive months with <40 mm rainfall|
|Mean annual rainfall||1300||3000||mm; lower/upper limits|
Rainfall RegimeTop of page Summer
Soil TolerancesTop of page
Special soil tolerances
Notes on Natural EnemiesTop of page A number of generalist pests and pathogens have been observed attacking A. confusa, though none are considered to be especially damaging.
Means of Movement and DispersalTop of page The species has been introduced outside its native range and it is possible that the species may become invasive in other areas where it has been introduced.
Impact SummaryTop of page
|Fisheries / aquaculture||None|
Impact: BiodiversityTop of page A. confusa reaches a height of 15 m and shades out many other species in Hawaii and it is suspected that the leaves have allelopathic properties because other species do not grow beneath it (PIER, 2002).
Threatened SpeciesTop of page
|Threatened Species||Conservation Status||Where Threatened||Mechanism||References||Notes|
|Peucedanum sandwicense (makou)||NatureServe NatureServe; USA ESA listing as threatened species USA ESA listing as threatened species||Hawaii||Competition - smothering||US Fish and Wildlife Service, 2011|
|Tetramolopium filiforme (ridgetop tetramolopium)||USA ESA listing as endangered species USA ESA listing as endangered species||Hawaii||Competition - monopolizing resources||US Fish and Wildlife Service, 2010|
Risk and Impact FactorsTop of page Invasiveness
- Proved invasive outside its native range
- Highly adaptable to different environments
- Tolerates, or benefits from, cultivation, browsing pressure, mutilation, fire etc
- Highly mobile locally
- Has high reproductive potential
- Damaged ecosystem services
- Ecosystem change/ habitat alteration
- Reduced native biodiversity
- Competition - monopolizing resources
- Competition - smothering
- Produces spines, thorns or burrs
UsesTop of page It is widely cultivated for coastal shelterbelt forests, soil and water conservation, fuelwood stands and for ornamental purposes. It also shows high potential for the pulp industry. It has a range of wood and non-wood end uses including amongst others, fuelwood, industrial and non-industrial domestic woodware, oils, bark products, honey and tannins.
Uses ListTop of page
- Erosion control or dune stabilization
- Shade and shelter
- Soil improvement
Human food and beverage
- Honey/honey flora
- Carved material
- Essential oils
- Miscellaneous materials
Wood ProductsTop of page
- Short-fibre pulp
- Industrial and domestic woodware
- Tool handles
Prevention and ControlTop of page Control of A. confusa is possible if saplings are treated with herbicides including 2,4-D and triclopyr, with sensitivity in varying degrees to cut-surface applications of 2,4-D, dicamba, glyphosate, picloram and triclopyr and to basal bark application of triclopyr in oil (PIER, 2002).
ReferencesTop of page
Chen DZ, 1988. China Flora. Beijing, China: Science Press, Vol. 39, 24.
Dou TL, 1983. Afforestation of light contained Acacia confusa seedling and its economic benefits. Sichuan Forest Science and Technology, 4(3):46-52.
Gui SZ, Shi MF, Fang CQ, 1987. Incident and control of Acacia confusa rust disease. Plant protection, Beijing. Vol. 4, 39-40.
Hirane S, 1938. Studies on the parasitism of the rust of Acacia confusa Merrill, Maravalia hyalospora (Saw.) Diet. II. Effects of the juice of phyllodes on the germination and germ-tube development of urediospores. Trans. nat. hist. Soc. Formosa 28; 29 1938; 1939 (421-30); (13-21).
Huag PQ, Wang LX, 1983. Silviculture of Major Plantation Trees in Guangdong Province. Guangdong, China: Guangdong Forest Science and Technology Press, pp. 108-111.
Huang TC; OHashi H, 1995. In Huang TC (ed.) Flora of Taiwan. Vol 3. Natural Science Council. Taipei, Taiwan: Roc. 2nd ed.
Lin HS, 1986. Comparative experiment of afforestation with Acacia confusa, A. mangium and A. auriculiformis. Guangdong Forest Science And Technology, 4:22-25.
Pan ZG, Yang MQ, 1988. Preliminary results of provenance trials with 5 tropical Acacia tree species at age of 3 years old. Forest Research, 5:553-557.
Tab XS, Wang GS, 1984. Root rot: A new disease of Acacia confusa. Hainan Reclamation Bureau. Forest Science and Technology, No. 9, 29.
US Fish and Wildlife Service, 2011. In: Endangered and Threatened Wildlife and Plants; Listing 23 Species on Oahu as Endangered and Designating Critical Habitat for 124 Species. 76(148) US Fish and Wildlife Service, 46362-46593. http://www.gpo.gov/fdsys/pkg/FR-2011-08-02/pdf/2011-17162.pdf
Wu ZY, 1984. Index Florae Yunnanensis. Yunnan, China: People's Publishing House.
Wu ZY, 1984. Index Florae Yunnanensis. Yunnan, China: The People's Publishing House.
Xu YQ, 1976. Major economic tree species in south China. Beijing, China: Agriculture Press.
Xu YQ, 1990. Forestry in Guangdong Province. Guangdong, China: Guangdong Science & Technology Press.
Yang MQ, 1990. Growth characteristics and adaptability of major tropical Acacia species in south China. Forest Research, 2:155-161.
Zhang HB, 1993. Forestry in Fujian Province. Beijing, China: China Forestry Publishing House, pp. 60-64.
Zhang XS, 1982. Survey of afforestation of Acacia confusa mixed with Pinus massoniana in aerial sowing. Guangdong Forest Science And Technology Communications, 4: 22-25.
Zheng WJ, 1978. Silvicultural techniques of major tree species in China. Beijing, China: Chinese Agriculture Publishing House, Vol. 2.
Zhong XR, 1981. An windfirm tree species: Acacia confusa. China Forestry, 11, 35.
Zhou XM, Li QM, 1983. Seedling growth of Acacia confusa, A. mangium and A. auriculiformis. Guangdong Forest Science and Technology Communication, 4, 18-19.
Distribution MapsTop of page
Unsupported Web Browser:
One or more of the features that are needed to show you the maps functionality are not available in the web browser that you are using.
Please consider upgrading your browser to the latest version or installing a new browser.
More information about modern web browsers can be found at http://browsehappy.com/