Galinsoga parviflora Carv., Asteraceae

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Present on Pacific Islands?  yes

Primarily a threat at high elevations?  no

Common name(s): [more details]

English: chick weed, ciliate galinsoga, galinsoga, gallant soldier, potato weed, quick weed, small-flower galinsoga, yellow weed

Japanese: hakidamegiku

Spanish: chuminca, guasco, pacuyuyo, rosilla chica

Habit:  herb

Description:  "Slender annual herbs 2-7 dm tall, sparsely pubescent with appressed or sometimes spreading hairs.  Leaves ovate or narrowly ovate, 2-5 cm long, 1-3 cm wide, margins serrulate or entire.  Heads 3-4 mm high, peduncles appressed pubescent or glandular villous; involucral bracts 2-3 mm long; ray florets (3) 5 (6) per head, rays white, rarely pink, 3-toothed, 1-2 mm long; pappus of ray florets absent or very reduced, that of disk florets consisting of blunt-tipped, fimbriate scales.  Achenes sparsely appressed pubescent or glabrous"  (Wagner et al., 1999; pp. 318-320).

Habitat/ecology:  "The plants grow best in moist conditions and can become very numerous under irrigation or in year-round rainfall in the tropics" (Holm et al., 1977; p. 280).

In Hawai‘i, "naturalized in a variety of disturbed habitats, particularly urban areas, trails, open rocky sites or pastures, 0-1,800 m" (Wagner et al., 1999; pp. 318-320).

Propagation:  "A prolific seeder, often producing several thousand per plant, it can complete a life cycle (germination to shedding of seeds) in as little as 50 days.  Viable seeds may be produced when the plant is only a few cm high.  These seeds may germinate readily after falling to the ground; however, germination may be retarded if the seed coat remains intact.  Light, as well as alternating temperatures, may favor germination.  Temperatures of 10° to 35° C appear to be suitable for germination" (Holm et al., 1977; p. 280).

Native range:  Southwestern US south to South American, now a cosmopolitan weed (Wagner et al., 1999; pp. 318-320).

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 worldwide weed of disturbed ground". Vouchers cited: J.D. McComish 128 (NSW); M.D. Crisp 4508 & I.R.H. Telford (CBG); 1920, J.L. Boorman (NSW)
Australia (Pacific offshore islands) Norfolk Islands	Norfolk Island	introduced invasive	Orchard, Anthony E., ed. (1994) (p. 8) "A worldwide weed of disturbed ground". Vouchers cited: W.R. Sykes NI 496 (CHR); P.S. Green 2411 (K); W.R. Sykes NI 188 (CHR); 1898, I. Robinson(NSW)
State of Hawaii Hawaiian Islands	Hawai‘i (Big) Island	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (pp. 318-320)
State of Hawaii Hawaiian Islands	Kaho‘olawe Island	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (pp. 318-320)
State of Hawaii Hawaiian Islands	Kaua‘i Island	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (pp. 318-320)
State of Hawaii Hawaiian Islands	Lāna‘i Island	introduced invasive	Oppenheimer, Hank (2008) (p. 24) Voucher cited: Oppenheimer, Perlman & Tangalin H10706 (BISH, PTBG)
State of Hawaii Hawaiian Islands	Maui Island	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (pp. 318-320)
State of Hawaii Hawaiian Islands	O‘ahu Island	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (pp. 318-320)
Papua New Guinea Papua New Guinea (eastern New Guinea Island)	Papua New Guinea (eastern New Guinea Island)	introduced invasive	Henty, E. E./Pritchard, G. H. (1975) (p. 76)
Philippines Philippine Islands	Philippine Islands	introduced invasive	Waterhouse, D. F. (1993) (pp. 66, 77)
Vanuatu New Hebrides Islands	Vanuatu (Republic of)		Swarbrick, John T. (1997) (p. 92)

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	introduced invasive	Holm, Leroy G./Plucknett, D. L./Pancho, J. V./Herberger, J. P. (1977) (p. 282)
Cambodia Cambodia	Cambodia (Kingdom of)	introduced invasive	Holm, Leroy G./Plucknett, D. L./Pancho, J. V./Herberger, J. P. (1977) (p. 282)
Chile (continental) Chile	Chile (Republic of)		Holm, Leroy G./Plucknett, D. L./Pancho, J. V./Herberger, J. P. (1977) (p. 282)
Colombia Colombia	Colombia (Republic of)		Holm, Leroy G./Plucknett, D. L./Pancho, J. V./Herberger, J. P. (1977) (p. 282)
Indonesia Indonesia	Indonesia (Republic of)	introduced invasive	Waterhouse, D. F. (1993) (pp. 66, 77)
Japan Japan	Japan (country)	introduced invasive	Holm, Leroy G./Plucknett, D. L./Pancho, J. V./Herberger, J. P. (1977) (p. 282)
Mexico Mexico	Mexico (United Mexican States)		Holm, Leroy G./Plucknett, D. L./Pancho, J. V./Herberger, J. P. (1977) (p. 282)
New Zealand New Zealand	New Zealand (country)	introduced invasive	Webb, C. J./Sykes, W. R./Garnock-Jones, P. J. (1988) (p. 218) "Locally abundant in gardens and cultivated land, also waste places and pasture".
Perú Perú	Perú (Republic of)		Holm, Leroy G./Plucknett, D. L./Pancho, J. V./Herberger, J. P. (1977) (p. 282)
Taiwan Taiwan	Taiwan Island	introduced invasive	Holm, Leroy G./Plucknett, D. L./Pancho, J. V./Herberger, J. P. (1977) (p. 282)
Thailand Thailand	Thailand (Kingdom of)	introduced invasive	Waterhouse, D. F. (1993) (pp. 66, 77)

Additional information:
Additional online information about Galinsoga parviflora is available from the Hawaiian Ecosystems at Risk project (HEAR).

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

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

References:

Henty, E. E./Pritchard, G. H. 1975. Weeds of New Guinea and their control. 2nd edition. Department of Forests, Division of Botany, Botany Bull. No. 7. Lae, Papua New Guinea. 180 pp.

Holm, Leroy G./Plucknett, D. L./Pancho, J. V./Herberger, J. P. 1977. The world’s worst weeds: distribution and biology. East-West Center/University Press of Hawaii. 609 pp.

Oppenheimer, Hank. 2008. New plant records from O‘ahu for 2007. In: Evenhuis, Neal L. and Eldredge, Lucias G., eds. Records of the Hawaii Biological Survey for 2007. Bishop Museum Occasional Papers 100:22-38.

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.

Swarbrick, John T. 1997. Weeds of the Pacific Islands. Technical paper no. 209. South Pacific Commission, Noumea, New Caledonia. 124 pp.

U. S. Government. 2009. Integrated Taxonomic Information System (ITIS) (on-line resource).

U.S. Dept. Agr., Agr. Res. Serv. 2009. 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).

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.