Acacia crassicarpa A. Cunningham ex Bentham, Fabaceae

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Present on Pacific Islands?  yes

Primarily a threat at high elevations?  no

Risk assessment results:  High risk, score: 7 (Go to the risk assessment)

Common name(s): [more details]

English: Northern Territory wattle, Papua New Guinea red wattle, black wattle, brown salwood, hickory wattle, northern golden wattle, northern wattle, thick-pod salwood

Maori (Cook Islands): ākasia

Habit:  tree

Description:  "A handsome tree of 30 to 40 ft. or more, glabrous and somewhat glaucous or hoary with a minute powdery pubescence. Branchlets scarcely angular. Phyllodia falcate-oblong, narrowed at both ends, 5 to 8 in. long, 1 to 2 in. broad, very oblique, some of the principal nerves confluent with the lower margin at the base, and numerous fine parallel veins between them, very rarely or not at all anastomosing. Spikes solitary or clustered, slender, not very dense, 1 in. long or rather more. Flowers mostly 5-merous. Calyx thin, sinuate-toothed, glabrous, about half as long as the corolla. Petals smooth but with the midrib prominent in the bud, united to the middle. Pod oblong, flat, thick, hard, obliquely veined, 2 to 3 in. long, 3/4 to nearly 1 in. broad, obliquely truncate at the base, occasionally slightly twisted. Seeds oblique, funicle not seen." (Bentham & Mueller, 1864; pp. 410-411).

Habitat/ecology:  "A. crassicarpa occurs mainly in the humid and sub-humid tropics from 8-20°S and from 0-200 (-450) m altitude.  Annual rainfall in its natural habitat is from as low as 500 mm in Australia to as high as 3500 mm in Papua New Guinea and Irian Jaya.  Length of the dry season ranges from 6 months at the southern limit of the distribution area near Townsville, Queensland, to 3 months at the northern limit in Papua New Guinea and Irian Jaya.  The mean minimum temperature of the coolest month is 15-22°C and the mean maximum temperature of the hottest month is 31-34°C.  No frost occurs in its natural range.  In Australia, A. crassicarpa is commonly found immediately behind beaches, on the coastal plains and foothills.  It appears to be tolerant of salt spray and soil salinity.  It occurs on a variety of soil types, from calcareous beach sands, yellow earths derived from granite, red earths on basic volcanic rock to alluvial and colluvial soils derived from a variety of parent material.  In Papua New Guinea and Irian Jaya it is found on the gently undulating terrain of the Oriomo Plateau, on well-drained, strongly acid soils, and also on imperfectly drained soils that flood in the wet season"  (Hanum &Van der Maesen, 1997; p. 57).

Propagation:  Seed

Native range:  Australia, New Guinea and Irian Jaya (Hanum &Van der Maesen, 1997; p. 56).

Presence:

Pacific
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
Cook Islands Southern Cook Islands	‘Atiu Island	introduced invasive cultivated	Space, James C./Flynn, Tim (2002) (p. 6) Voucher: Flynn 7096 (PTBG, BISH, US)
Cook Islands Southern Cook Islands	‘Atiu Island		National Tropical Botanical Garden (U.S.A. Hawaii. Kalaheo.) (2002) (voucher ID: PTBG 392) Taxon name on voucher: Acacia crassicarpa
Cook Islands Southern Cook Islands	Mangaia Island	introduced invasive cultivated	Space, James C./Flynn, Tim (2002) (p. 6) Voucher: Flynn 7043 (PTBG, BISH, US)
Cook Islands Southern Cook Islands	Mangaia Island		National Tropical Botanical Garden (U.S.A. Hawaii. Kalaheo.) (2002) (voucher ID: PTBG 366) Taxon name on voucher: Acacia crassicarpa
Cook Islands Southern Cook Islands	Ma‘uke Island	introduced invasive cultivated	Space, James C./Flynn, Tim (2002) (p. 6) Vouchers: Flynn 7072 (PTBG, BISH, US), Flynn 7073 (PTBG, BISH, US)
Cook Islands Southern Cook Islands	Ma‘uke Island		National Tropical Botanical Garden (U.S.A. Hawaii. Kalaheo.) (2002) (voucher ID: PTBG 379) Taxon name on voucher: Acacia crassicarpa
Cook Islands Southern Cook Islands	Ma‘uke Island		National Tropical Botanical Garden (U.S.A. Hawaii. Kalaheo.) (2002) (voucher ID: PTBG 380) Taxon name on voucher: Acacia crassicarpa
New Guinea (Indonesia and Papua New Guinea) New Guinea Island	New Guinea Island	native	Australian Biological Resources Study (2013)
Papua New Guinea Papua New Guinea (eastern New Guinea Island)	Papua New Guinea (eastern New Guinea Island)	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)

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	native	Australian Biological Resources Study (2013)
Indonesia Indonesia	West Papua Province (Indonesia) (western New Guinea Island) (formerly Irian Jaya)	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
Thailand Thailand	Thailand (Kingdom of)	introduced cultivated	U.S. Dept. Agr., Agr. Res. Serv. (2013)

Comments:  Established in forestry plantations and spreading on ‘Atiu, Mangaia and Ma‘uke, Cook Islands (Space & Flynn, 2002).

Control:  If you know of control methods for Acacia crassicarpa, please let us know.