Ludwigia hyssopifolia (G.Don) Exell, Onagraceae

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Present on Pacific Islands?  yes

Primarily a threat at high elevations?  no

Other Latin names:  Jussiaea hyssopifolia G. Don; Jussiaea linifolia Vahl

Common name(s): [more details]

Chamorro: charguan asusuyan, titimo

Chinese: cao long

Fijian: nai qisa

Marshallese: utilolõb

Palauan: erur

Pohnpeian: delahrik

Spanish: mimbra

Habit:  herb

Description:  "An erect, annual herbaceous, marshy, or aquatic plant, at times seen on drier land, to 3 m high, sometimes persisting and becoming woody at the base; stems nearly glabrous, green but may have reddish or purplish coloration, marked with striations, usually branched above, may appear 3- or 4-angled, young growth and inflorescence minutely pubescent; leaves lanceolate to linear lanceolate, narrowly cuneate at base, acute to acuminate at tip, may be white-green, up to 10 cm long, 1 to 3 cm wide, petiole short, midrib may be white-green, margin may be serrulate, glabrous or with few short hairs at base of leaf; flowers small, axillary, solitary, sessile; calyx a tube surrounding the inferior ovary, forming at the top 4 lanceolate, acuminate sepals, 2 to 4 mm long, pubescent; petals 4, yellow or white fading to orange-yellow, ovate to elliptic, a little larger than sepals; style and stigma simple, style pale greenish-yellow, stigma globose, stamens 8, in this species filaments of the epipetalous stamens are 0.5 to 1 mm long, those of the episepalous being 1 to 2 mm long; fruit a capsule, cylindrical, 4-celled, up to 3 cm long, l to 0.2 mm wide, pubescent, subsessile, somewhat enlarged at top; seeds of two types: those of the upper part of capsule numerous, several rows per locule, ovoid, about 0.5 mm long, free, more pale brown than lower seeds; in lower capsule 1 row per locule, about 0.75 mm long, brown, each imbedded in a corky disc.  This plant may be distinguished from L. adscendens and L. octovalvis by its unusual dimorphous seeds"  (Holm et al., 1997; p. 450).

"Annual herb to 1 (rarely 2-3) m tall, young growth and inflorescence minutely puberulent; leaves lanceolate, up to 9 cm long and 3 cm wide, acuminate, cuneate basally, lateral nerves 11-17 pairs; petiole up to 1.8 cm long; sepals 4, 2-4 mm long, lanceolate; petals 4, yellow, 2-3 mm long, elliptic; stamens 8, slightly unequal, 0.5-2 mm long (excl. anthers); fruit capsular, finely puberulent, 1.5-3 cm long, about 1 mm thick, subsessile; seeds of 2 kinds, those of lower section of capsule 0.7-0.85 mm long, those in upper section 0.35-0.5 mm long"  (Stone, 1970; p. 457).

Habitat/ecology:  "It is known to frequent pools, shallow ditches, and river edges.  It grows in rice and in fallow garden lands and wastelands in humid areas.  In Borneo, it prospers in clearings on both heavy clay and coarse white sand, as well as in pools in eucalyptus savannahs.  It has been found at 1000 m in old volcanic mudstreams on Java" (Holm et al., 1997; p. 452).

In Guam, "a weed of ditches, ponds, rice-fields, etc., up to 500 m altitude"  (Stone, 1970; p. 457).  In Fiji, "occurs locally at low elevations as a naturalized weed 0.5-1 m high, found along roadsides, in ricefields, and in other wet places" (Smith, 1985; p. 381).  "Occasional in taro crops, pastures and wet roadside ditches" (Whistler, 1988; p. 31). In New Guinea (native), "a plant of wet places; swamps and stream edges, roadside ditches; often a weed of pastures. Mostly from sea level to 700 m" (Henty & Pritchard, 1975; p. 129); "a plant of wet places; swamps and stream edges, roadsides or shallow water ditches.  In Papuasia, it is widespread in the lowlands and up to c. 3000 m altitude"  (Conn, 1995; p. 210).

Propagation:  Seed. "The lower seeds in the capsule, being provided with floats, may be water-dispersed" (Henty & Pritchard, 1975; p. 129).

Native range:  Africa, Asia and the Pacific (Stone, 1970; p. 457).  "The place of origin of this pantropical weed is uncertain; it is relatively local in Africa and the Cape Verde Islands, also occurring from Ceylon, India, and southern China throughout Malesia to Micronesia and northern Australia, with apparently recent populations in Fiji and Samoa." (Smith, 1985; p. 381)   Fosberg et al. (1979; p. 195) list as native to Micronesia.

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. 31) Voucher cited: Lamoureux 3052
Commonwealth of the Northern Mariana Islands (US) Northern Mariana Islands	Rota Island	native	Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1979) (p. 195)
Federated States of Micronesia Chuuk Islands	Chuuk Islands		Swarbrick, John T. (1997) (p. 94)
Federated States of Micronesia Kosrae Island	Kosrae Island	introduced invasive	Lorence, David H./Flynn, Timothy (2010) (p. 21) Naturalized
Federated States of Micronesia Kosrae Island	Kosrae Island		National Tropical Botanical Garden (U.S.A. Hawaii. Kalaheo.) (1996) (voucher ID: PTBG 24871) Taxon name on voucher: Ludwigia hyssopifolia (G. Don) Exell
Federated States of Micronesia Pohnpei Islands	Pohnpei Island	native	Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1979) (p. 195)
Federated States of Micronesia Pohnpei Islands	Pohnpei Island		Glassman, S. F. (1952) (p. 58) Voucher cited: Glassman 2915 (US)
Federated States of Micronesia Pohnpei Islands	Pohnpei Island	introduced invasive	Herrera, Katherine/Lorence, David H./Flynn, Timothy/Balick, Michael J. (2010) (p. 119) Vouchers cited: M.J. Balick 4129 (NY, PTBG), E. Eperiam 3 (NY), F.R. Fosberg 58494 (BISH), F.R. Fosberg 60454 (BISH), S.F. Glassman 2915 (BISH), N.L.. Krauss 1893C (BISH), N.L.H. Krauss 1894c (BISH), P. Raynor 138 (NY), M. Takamatsu 787 (BISH), M. Takamatsu 1040 (BISH), N.S. Tangalin 1270 (BISH) Naturalized
Federated States of Micronesia Pohnpei Islands	Pohnpei Island		National Tropical Botanical Garden (U.S.A. Hawaii. Kalaheo.) (1980) (voucher ID: PTBG 23347) Taxon name on voucher: Ludwigia hyssopifolia
Federated States of Micronesia Pohnpei Islands	Pohnpei Island		National Tropical Botanical Garden (U.S.A. Hawaii. Kalaheo.) (2000) (voucher ID: PTBG 43408) Taxon name on voucher: Ludwigia hyssopifolia
Federated States of Micronesia Pohnpei Islands	Pohnpei Island		National Tropical Botanical Garden (U.S.A. Hawaii. Kalaheo.) (2007) (voucher ID: PTBG 50094) Taxon name on voucher: Ludwigia hyssopifolia
Federated States of Micronesia Yap Islands	Yap (Waqab) Island	native	Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1979) (p. 195)
Fiji Fiji Islands	Viti Levu Island	introduced invasive	Smith, Albert C. (1985) (p. 381) Vouchers cited: DA 10825, DA 10050, DA 6025, DA 11736, DA L.10508
French Polynesia Society Islands	Raiatea (Havai) Island		Fosberg, F. R. (1997) (p. 85)
French Polynesia Society Islands	Tahiti Island		Fosberg, F. R. (1997) (p. 85)
Guam Guam Island	Guam Island	introduced invasive	Stone, Benjamin C. (1970) (p. 457) Voucher cited: Rodin 819
Guam Guam Island	Guam Island	native	Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1979) (p. 195)
Japan (offshore islands) Ogasawara (Bonin) Islands	Bonin (Ogasawara) Islands		Kato, Hidetoshi (2007)
Marshall Islands Ratak Chain	Likiep Atoll	native	Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1979) (p. 195)
Palau Palau (Belau ) (main island group)	Angaur (Ngeaur) Island	native	Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1979) (p. 195)
Palau Palau (Belau ) (main island group)	Babeldaob Island	native	Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1979) (p. 195)
Palau Palau (Belau ) (main island group)	Babeldaob Island	native	Space, James C./Waterhouse, Barbara/Miles, Joel E./Tiobech, Joseph/Rengulbai, Kashgar (2003) (p. 101)
Palau Palau (Belau ) (main island group)	Babeldaob Island	native	Space, James C./Lorence, David H./LaRosa, Anne Marie (2009) (p. Field notes)
Palau Palau (Belau ) (main island group)	Babeldaob Island		Beleu National Museum (Republic of Palau. Koror.) (1966) (voucher ID: BNM 587) Taxon name on voucher: Ludwigia hyssopifolia (G. Don) Exell
Palau Palau (Belau ) (main island group)	Babeldaob Island		Beleu National Museum (Republic of Palau. Koror.) (1970) (voucher ID: BNM 588) Taxon name on voucher: Ludwigia hyssopifolia (G. Don) Exell
Palau Palau (Belau ) (main island group)	Babeldaob Island		Beleu National Museum (Republic of Palau. Koror.) (1981) (voucher ID: BNM 3101) Taxon name on voucher: Ludwigia hyssopifolia (G. Don) Exell
Palau Palau (Belau ) (main island group)	Koror (Oreor) Island	native	Space, James C./Waterhouse, Barbara/Miles, Joel E./Tiobech, Joseph/Rengulbai, Kashgar (2003) (p. 98)
Palau Palau (Belau ) (main island group)	Malakal (Ngemelachel) Island	native	Space, James C./Waterhouse, Barbara/Miles, Joel E./Tiobech, Joseph/Rengulbai, Kashgar (2003) (p. 98)
Palau Palau (Belau ) (main island group)	Ngerkebesang Island	native	Space, James C./Waterhouse, Barbara/Miles, Joel E./Tiobech, Joseph/Rengulbai, Kashgar (2003) (p. 98)
Papua New Guinea Papua New Guinea (eastern New Guinea Island)	Papua New Guinea (eastern New Guinea Island)		Henty, E. E./Pritchard, G. H. (1975) (p. 129) Widespread, mostly from sea level to 700 m.
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)
Papua New Guinea Papua New Guinea (eastern New Guinea Island)	Papua New Guinea (eastern New Guinea Island)	native	Conn, Barry J., ed. (1995) (pp. 209-210)
Philippines Philippine Islands	Philippine Islands	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
Samoa Western Samoa Islands	Upolu Island	introduced invasive	Smith, Albert C. (1985) (p. 381)
Samoa Western Samoa Islands	Upolu Island		Whistler, W. A. (1988) (p. 31) Voucher cited: Parham 9018
Samoa Western Samoa Islands	Upolu Island	introduced invasive	Space, James C./Flynn, Tim (2002) (p. Field notes.) Voucher: Flynn 6937 (PTBG, US, SAMOA)
Samoa Western Samoa Islands	Upolu Island		National Tropical Botanical Garden (U.S.A. Hawaii. Kalaheo.) (2002) (voucher ID: PTBG 321) Taxon name on voucher: Ludwigia hyssopifolia (G.Don) Exell
Samoa Western Samoa Islands	Upolu Island		National Tropical Botanical Garden (U.S.A. Hawaii. Kalaheo.) (2002) (voucher ID: PTBG 41439) Taxon name on voucher: Ludwigia hyssopifolia (G. Don) Exell
Solomon Islands Solomon Islands	Solomon Islands		Swarbrick, John T. (1997) (p. 94)

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)	Northern Territory	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
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)	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
Central America Central America (Pacific rim)	Guatemala (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
Central America Central America (Pacific rim)	Honduras (Republic of)		Holm, Leroy/Pancho, Juan V./Herberger, James P./Plucknett, Donald L. (1979) (p. 221)
Central America Central America (Pacific rim)	Nicaragua (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
Central America Central America (Pacific rim)	Panama (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
China China	China (People's Republic of)	native	Zhengyi, Wu/Raven, Peter H./Deyuan, Hong (2013) Scattered to common in open wet often disturbed areas, streamsides, roadside ditches, clear agricultural land, or openings in moist forests; near sea level to 800 m. Fujian, Guangdong, Guangxi, Hainan, Yunnan.
Indonesia Indonesia	Indonesia (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
Japan Japan	Japan		Holm, Leroy/Doll, Jerry/Holm, Eric/Pancho, Jaun/Herberger, James (1997) (p. 450)
Malaysia Malaysia	Malaysia (country of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
Mexico Mexico	Mexico (United Mexican States)	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
Negara Brunei Darussalam Brunei	Brunei (Negara Brunei Darussalam)		Waterhouse, D. F. (1993) (pp. 66, 78)
Singapore Singapore	Singapore (Republic of)		Waterhouse, D. F. (1993) (pp. 66, 78)
Singapore Singapore	Singapore (Republic of)	uncertain if introduced invasive	Chong, Kwek Yan/Tan, Hugh T. W./Corlett, Richard T. (2009) (p. 57) Weed of uncertain origin
South America (Pacific rim) South America (Pacific rim)	Colombia	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
South America (Pacific rim) South America (Pacific rim)	Ecuador (Republic of) (continental)	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
South America (Pacific rim) South America (Pacific rim)	Perú (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
Taiwan Taiwan Island	Taiwan Island	native	Zhengyi, Wu/Raven, Peter H./Deyuan, Hong (2013) Scattered to common in open wet often disturbed areas, streamsides, roadside ditches, clear agricultural land, or openings in moist forests; near sea level to 800 m.
Taiwan Taiwan Island	Taiwan Island	native	Ching-I Peng, ed. (2013) "Weed of wet places at low elevations".
Thailand Thailand	Thailand (Kingdom of)		Waterhouse, D. F. (1993) (pp. 66, 78)
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
Australia (Indian Ocean offshore islands) Christmas Island Group	Christmas Island	introduced invasive	Orchard, Anthony E., ed. (1993) (p. 19)
Seychelles Seychelles Islands	Seychelles Islands	introduced	Invasive Species Specialist Group (2017)

Control:  If you know of control methods for Ludwigia hyssopifolia, please let us know.