Youngia japonica (L.) DC., Asteraceae

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Present on Pacific Islands?  yes

Primarily a threat at high elevations?  no

Other Latin names:  Crepis japonica Benth.; Prenanthes japonica L.

Common name(s): [more details]

Chinese: huang an cai

English: asiatic hawksbeard, oriental false hawksbeard, oriental hawksbeard

Fijian: mosita ni Viti

Tongan: fisi puna

Habit:  herb

Description:  "Erect, pubescent herb, the leaves mostly in basal rosette, stem with a few cauline leaves; basal leaves petiolate, oblanceolate, pinnately parted, lyrate, finely dentate, usually puberulent, about 3-15 cm long and up to 5 cm wide, the terminal lobe largest; cauline leaves usually only 1-3, subsessile, much smaller; heads several to many in a panicle, 7-8 mm wide; involucre 5-6 mm long, with about 8 inner (longer) bracts; florets about 10-25; corolla about 5-6 mm long, yellow; achenes brown, about 1.8 mm long, with slender scaberulous ribs; pappus soft, white, 3 mm long, persistent"  (Stone, 1970; p. 579).

Description from the Flora of China online.
Description from the Flora of North America online.

Habitat/ecology:  In Guam, "found usually in shady spots near houses" (Stone, 1970; p. 579). In Hawai‘i, "a common weed in often moist and shaded, disturbed sites, but also occurring in nearly intact wet forest, 0-1,400 m" (Wagner et al., 1999; p. 377).  In Fiji, "found from near sea level to about 1,100 m as a weed in gardens and villages, on cleared land, and along roadsides and forest trails" (Smith, 1991; p. 267).  In New Guinea, "sometimes common in natural grassland at median altitudes, and an occasional weed of cultivation and plantations, particularly after other more vigorous weeds have been suppressed. Occurring at altitudes from 1000 to 3000 m" (Henty & Pritchard, 1975; p. 88). In New Caledonia, "largement répandu comme mauvaise herbe de jardin et en lieux frais incultes" (MacKee, 1994; p. 39). "Occasional in disturbed places, especially in lawns" (Whistler, 1988; p. 13). In China (native), "mountain slopes, mountain valleys, ravines, forests, forest margins, grasslands, moist areas, by water, stream banks, trailsides, roadsides, disturbed places, densely grassy areas by houses or roads, field margins, as a weed in gardens and fields; below 100-4500 m"  (Flora of China online).

Propagation:  Seed

Native range:  East Asia, Malaysia, India to Australia and some Pacific islands (Stone, 1970; p. 579).  "Japan, Korea, western China, and northwestern India to Malesia, widely adventive elsewhere" (Smith, 1991; p. 267).

Presence:

Pacific
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
American Samoa Tutuila Islands	Tutuila Island		Whistler, W. A. (1988) (p. 13) Not common per Whistler. Voucher cited: Whistler 5733
Commonwealth of the Northern Mariana Islands (US) Northern Mariana Islands	Rota Island	introduced	Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1979) (p. 294)
Commonwealth of the Northern Mariana Islands (US) Saipan	Saipan Island	introduced	Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1979) (p. 294)
Cook Islands Southern Cook Islands	Mangaia Island		McCormack, Gerald (2013)
Fiji Fiji Islands	Viti Levu Island	introduced invasive	Smith, Albert C. (1991) (p. 267) Vouchers cited: Greenwood 801, DA 10410, Vaughan 3237, Smith 4794, Smith 8814, St. John 18305, DA 9576, DA 5624, DA 11105, DA 10066, DA 11475, DA 12607
French Polynesia Society Islands	Raiatea (Havai) Island	introduced invasive	Welsh, S. L. (1998) (p. 82) Voucher cited: BRY 26629
French Polynesia Society Islands	Tahiti Island	introduced invasive	Welsh, S. L. (1998) (p. 82) Vouchers cited: BRY 25988, BRY 26041, Fosberg & Stone 61287
French Polynesia Society Islands	Tahiti Island	introduced invasive	Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. (2013) Vouchers cited: J. Florence 2437 (PAP), J. Florence 2530 (PAP), J. Florence 2759 (PAP), J. Florence 2912 (PAP), J. Florence 8758 (PAP), P. Birnbaum 5 (PAP) Adventice
French Polynesia Society Islands	Tahiti Island		National Tropical Botanical Garden (U.S.A. Hawaii. Kalaheo.) (1981) (voucher ID: PTBG 37214) Taxon name on voucher: Youngia japonica (L.) DC.
French Polynesia Austral (Tubuai) Islands	Rimatara (Rimitara) Island	introduced invasive	Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. (2013) Adventice
French Polynesia Austral (Tubuai) Islands	Rurutu Island	introduced invasive	Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. (2013) Adventice
French Polynesia Austral (Tubuai) Islands	Tubuai Island	introduced invasive	Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. (2013) Adventice
Guam Guam Island	Guam Island	introduced invasive	Stone, Benjamin C. (1970) (p. 579)
Guam Guam Island	Guam Island	introduced	Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1979) (p. 294)
State of Hawaii Hawaiian Islands	Hawai‘i (Big) Island	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 377)
State of Hawaii Hawaiian Islands	Kaua‘i Island	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 377)
State of Hawaii Hawaiian Islands	Lāna‘i Island	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 377)
State of Hawaii Hawaiian Islands	Maui Island	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 377)
State of Hawaii Hawaiian Islands	Moloka‘i Island	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 377)
State of Hawaii Hawaiian Islands	O‘ahu Island	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 377)
Japan (offshore islands) Ogasawara (Bonin) Islands	Bonin (Ogasawara) Islands		Kato, Hidetoshi (2007)
Marshall Islands Ratak Chain	Majuro (Mãjro) Atoll	introduced	Vander Velde, Nancy/Vander Velde, Brian (2009) (p. 1) Voucher cited: Vander Velde 0520200901
Marshall Islands Ratak Chain	Majuro (Mãjro) Atoll		National Tropical Botanical Garden (U.S.A. Hawaii. Kalaheo.) (2009) (voucher ID: PTBG 49755) Taxon name on voucher: Youngia japonica
New Caledonia New Caledonia Archipelago	Île Grande Terre	introduced invasive	Tassin, Jacques (2005)
New Caledonia New Caledonia Archipelago	Île Grande Terre	introduced invasive	MacKee, H. S. (1994) (pp. 39-40) Vouchers cited: Brousmiche s.n., Rordorf s.n. (Z), MacKee 2404, MacKee 5133, MacKee 12080, MacKee 17615, MacKee 40668
New Caledonia New Caledonia Archipelago	Île des Pins (Isle of Pines)	introduced invasive	Tassin, Jacques (2005)
New Caledonia New Caledonia Archipelago	Île des Pins (Isle of Pines)	introduced invasive	MacKee, H. S. (1994) (pp. 39-40) Voucher cited: MacKee 33820
Niue Niue	Niue Island	introduced invasive	Whistler, W. A. (1988) (p. 13)
Palau Palau (Belau ) (main island group)	Koror (Oreor) Island	introduced invasive	Space, James C./Waterhouse, Barbara/Miles, Joel E./Tiobech, Joseph/Rengulbai, Kashgar (2003) (p. 99)
Palau Palau (Belau ) (main island group)	Koror (Oreor) Island	introduced invasive	Fosberg, F. R./Canfield, Joan E. (1980) (p. 200) Voucher cited: Otobed PW-10181
Papua New Guinea Bismarck Archipelago	Bismarck Archipelago		Peekel, P. G. [translated by E. E. Henty] (1984) (p. 567) Scattered, not abundant.
Papua New Guinea Bougainville Islands	Bougainville Island		Foreman, D. B. (1971) (p. 38)
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. 88) Occuring at altitudes from 1000 to 3000 m.
Philippines Philippine Islands	Philippine Islands	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
Philippines Philippine Islands	Philippine Islands		Merrill, Elmer D. (1923) (p. 622) As Crepis japonica. In old clearings, ravines, etc., chiefly at medium and higher altitudes.
Solomon Islands Solomon Islands	Solomon Islands		Swarbrick, John T. (1997) (p. 98)
Solomon Islands Solomon Islands	Solomon Islands	native	Hancock, I. R./Henderson, C. P. (1988) (p. 118)
Tonga Tongatapu Group	‘Eua Island		Whistler, W. A. (1992) (p. 9) Voucher cited: Soakai 949 (EI)
Tonga Tongatapu Group	Tongatapu Island		Whistler, W. A. (1992) (p. 9) Vouchers cited: Lawrence 62, Ilolahia 54, Soakai 723, Soakai 1002
Tonga Tongatapu Group	Tongatapu Island	introduced invasive	Yuncker, T. G. (1959) (p. 271) Vouhcer cited: Yuncker 15227

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)	New South Wales	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
Australia Australia (continental)	Australia (continental)		Holm, Leroy/Pancho, Juan V./Herberger, James P./Plucknett, Donald L. (1979) (p. 389)
Australia Australia (continental)	Queensland	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
Cambodia Cambodia	Cambodia (Kingdom of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
Central America Central America (Pacific rim)	Costa Rica (Republic of)	introduced invasive	U.S. Dept. Agr., Agr. Res. Serv. (2013) Naturalized
Central America Central America (Pacific rim)	Panama (Republic of)	introduced invasive	U.S. Dept. Agr., Agr. Res. Serv. (2013) Naturalized
China China	China (People's Republic of)	native	Zhengyi, Wu/Raven, Peter H./Deyuan, Hong (2013)
China China	Hong Kong	native	Wu, Te-lin (2001) (p. 290) In wasteland.
Japan Japan	Japan	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
Japan Japan	Japan		Holm, Leroy/Pancho, Juan V./Herberger, James P./Plucknett, Donald L. (1979) (p. 389)
Japan Ryukyu Islands	Ryukyu Islands	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
North Korea North Korea	North Korea (Democratic People's Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
South Korea South Korea	South Korea (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
Malaysia Malaysia	Malaysia (country of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
Mexico Mexico	Mexico (United Mexican States)	introduced invasive	U.S. Dept. Agr., Agr. Res. Serv. (2013) Naturalized
Singapore Singapore	Singapore (Republic of)	introduced invasive	Chong, Kwek Yan/Tan, Hugh T. W./Corlett, Richard T. (2009) (p. 91) Naturalised
Taiwan Taiwan Island	Taiwan Island		Holm, Leroy/Pancho, Juan V./Herberger, James P./Plucknett, Donald L. (1979) (p. 389)
Taiwan Taiwan Island	Taiwan Island	uncertain if native	Ching-I Peng, ed. (2013) "Very common in wastelands, cultivated fields and on roadsides".
Thailand Thailand	Thailand (Kingdom of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
Vietnam Vietnam	Vietnam (Socialist Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)

Indian Ocean
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
Comoros Comoro Islands	Comoro Islands	introduced invasive	U.S. Dept. Agr., Agr. Res. Serv. (2013) Naturalized
La Réunion (France) La Réunion Island	La Réunion Island	introduced invasive	U.S. Dept. Agr., Agr. Res. Serv. (2013) Naturalized
Mauritius Mautitius Islands (Mauritius and Rodrigues)	Mauritius Island	introduced invasive	U.S. Dept. Agr., Agr. Res. Serv. (2013) Naturalized
Mauritius Mautitius Islands (Mauritius and Rodrigues)	Mauritius Island		Holm, Leroy/Pancho, Juan V./Herberger, James P./Plucknett, Donald L. (1979) (p. 389)
Seychelles Seychelles Islands	Seychelles Islands	introduced	Invasive Species Specialist Group (2017)

Also reported from
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
United States (continental except west coast) United States (other states)	United States (other states)	introduced	U.S. Dept. Agr., Nat. Res. Cons. Serv. (2013)
United States (continental except west coast) United States (other states)	USA (Florida)	introduced	U.S. Dept. Agr., Nat. Res. Cons. Serv. (2013)

Control:  If you know of control methods for Youngia japonica, please let us know.