Ageratina adenophora (Spreng.) R.M.King & H.Rob., Asteraceae

Click on an image for links to BIGGER PICTURES

Present on Pacific Islands?  yes

Primarily a threat at high elevations?  no

Other Latin names:  Eupatorium adenophorum Spreng.; Eupatorium glandulosum Michx.

Common name(s): [more details]

English: catweed, croftonweed, hemp agrimony, Mexican devil, pamakani, sticky agrimony, sticky snakeroot, white thoroughwort

Hawaiian: Maui pāmakani, pāmakani haole

Habit:  herb

Description:  "Malodorous subshrubs; stems often purple, erect, usually 5-15 dm long, unbranched to branched, densely glandular puberulent and puberulent.  Leaves darker on upper surface, rhombic to deltate, 4-15 cm long, 1-6 (-8) cm wide, margins coarsely serrate, petioles usually 1-6 cm long.  Inflorescences strictly erect; involucral bracts 3-5 mm long, glandular puberulent; corollas white, ca. 3 mm long.  Achenes reddish brown, ca. 1.5 mm long." (Wagner et al., 1999; p. 254).

Habitat/ecology:  In Hawai‘i, "naturalized from relatively dry areas to wet forest, 600-2,000 m" (Wagner et al., 1999; p. 254).

Propagation:  Seed

Native range:  Mexico (Wagner et al., 1999; p. 254).

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. 205)
Australia (Pacific offshore islands) Lord Howe Island	Lord Howe Island	introduced invasive	Orchard, Anthony E., ed. (1994) (p. 18) "A Central American adventive which is invading open areas in the forest and should be urgently controlled". Vouchers cited: G. Uhe 1284 (K), L.A.S. Johnson & A.N. Rodd 1307 (NSW), P.S. Green 1969 (K), R.D. Hoogland 8730 (NSW), J. Pickard 2766 (NSW)
French Polynesia Society Islands	Tahiti Island	introduced invasive	Welsh, S. L. (1998) (p. 69) Voucher cited: BRY 24873
State of Hawaii Hawaiian Islands	Kaua‘i Island	introduced	Wester, Lyndon (1992) (p. 127)
State of Hawaii Hawaiian Islands	Lāna‘i Island	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (pp. 254-255)
State of Hawaii Hawaiian Islands	Maui Island	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (pp. 254-255)
State of Hawaii Hawaiian Islands	Moloka‘i Island	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (pp. 254-255) Voucher cited: Rock 6133 (BISH)
State of Hawaii Hawaiian Islands	O‘ahu Island	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (pp. 254-255)
Philippines Philippine Islands	Philippine Islands		Waterhouse, D. F. (1993) (p. 63)

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 invasive	U.S. Dept. Agr., Agr. Res. Serv. (2009)
China China	China (People's Republic of)	introduced invasive	Li-ying, Li/Ren, Wang/Waterhouse, D. F. (1997) (pp. 172, 178)
Indonesia Indonesia	Indonesia (Republic of)		Waterhouse, D. F. (1993) (p. 63)
Mexico Mexico	Mexico (United Mexican States)	native	U.S. Dept. Agr., Agr. Res. Serv. (2009)
Negara Brunei Darussalam Brunei	Brunei (Negara Brunei Darussalam)		Waterhouse, D. F. (1993) (p. 63)
New Zealand New Zealand	New Zealand (country)	introduced invasive	Webb, C. J./Sykes, W. R./Garnock-Jones, P. J. (1988) (p. 205) "Usually forest margins and clearings, waste places, scrubland, streamsides, rarely in swamps".
Thailand Thailand	Thailand (Kingdom of)		Waterhouse, D. F. (1993) (p. 63)
United States (west coast) United States (west coast states)	USA (California)	introduced invasive	U.S. Dept. Agr., Nat. Res. Cons. Serv. (2009)

Comments:  A declared noxious weed in the United States.

Control: 

Physical: "May be controlled by slashing, followed by ripping or plowing, then sowing desirable pasture species"  (Motooka et al., 2003).

Chemical: "Herbicides used to control this plant include glyphosate, 2,4-D amine, dicamba and MCPA, or triclopyr, applied in late summer when the plant is actively growing"  (Weber, 2003; p. 28).

Biological:  "Successful biological control has been achieved in Hawaii by the introduction of the Trypetid gallfly, Procecidochares utilis, a species which has also caused considerable mortality in parts of Australia, South Africa, New Zealand and India" (Cronk & Fuller, 2001; p. 134).  In Hawai‘i, "Under control by the fungus Cercosporella sp., but populations flare locally at times.  Susceptible to hormone-type herbicides and glyphosate"  (Motooka et al., 2003).

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).
Information from the Australian National Weed Strategy.
Photos and additional information at the Environment Bay of Plenty, New Zealand, web site of the Bay of Plenty Regional Council.
Fact sheet from the Government of Queensland, Australia. (PDF format).

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

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

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

Other Latin names:  Eupatorium adenophorum Spreng.; Eupatorium glandulosum Michx.

References:

Cronk, Q. C. B./Fuller, J. L. 2001. Plant invaders. Earthscan Publications, Ltd., London. 241 pp.

Li-ying, Li/Ren, Wang/Waterhouse, D. F. 1997. The distribution and importance of arthropod pests and weeds of agriculture and forestry plantations in southern China. ACIAR, Canberra, Australia. 185 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.

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

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

U.S. Dept. Agr., Agr. Res. Serv. 2009. National Genetic Resources Program. Germplasm Resources Information Network (GRIN). Online searchable database.

U.S. Dept. Agr., Nat. Res. Cons. Serv. 2009. The PLANTS Database. National Plant Data Center, Baton Rouge, LA 70874-4490 USA.

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).

Waterhouse, D. F. 1993. The major arthropod pests and weeds of agriculture in Southeast Asia. The Australian Centre for International Agricultural Research, Canberra. 141 pp.

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.

Welsh, S. L. 1998. Flora Societensis: A summary revision of the flowering plants of the Society Islands. E.P.S. Inc., Orem, Utah. 420 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. .