Oxalis debilis Kunth, Oxalidaceae

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Present on Pacific Islands?  yes

Primarily a threat at high elevations?  no

Other Latin names:  Oxalis corymbosa DC.

Common name(s): [more details]

English: lilac oxalis, pink wood sorrel

Hawaiian: ‘ihi pehu

Habit:  herb

Description:  "Acaulescent perennial herbs from an ovoid bulb 2-2.5 cm long, covered with brownish ovate scales, maturing into masses of brown ovoid bulbils 3-6 mm in diameter in the axils of the old scales.  Leaves trifoliolate, leaflets broadly obcordate, often drooping, 1.5-4.5 cm long, 2-6.5 cm wide, glabrous or sparsely pubescent, both surfaces covered with minute reddish tubercles, petioles slender, flexuous, ascending, 10-25 cm long, more or less villous, stipules small, membranous, adnate to petioles.  Flowers 2-12 in umbellate cymes, peduncles up to 35 cm long, usually villous, bracts several, ovate-lanceolate, 2.5-3 mm long; sepals oblong, 3.5-5 (-6) mm long; petals pinkish purple, spatulate, 11-20 mm long, apex obtuse to truncate; ovules 3-8 per cell, in 1-2 rows" (Wagner et al., 1999; pp. 1002, 1004, 1887).

Habitat/ecology:  In Hawai‘i, "naturalized and sometimes locally common, usually in relatively wet, shaded sites, 10-850 m" (Wagner et al., 1999; pp. 1002, 1004).  In Fiji, "occasionally cultivated and frequently naturalized in gardens, waste places, and along trails near sea level" (Smith, 1985; p. 109).  In the Pacific, "an occasional garden ornamental, now escaped and becoming a weed of waste places and cultivated land, difficult to eradicate" (Smith, 1985; p. 627). In New Caledonia, "mauvaise herbe répandue mais pas très gênante" (MacKee, 1994; p. 109). Moist uplands in the Galápagos Islands (McMullen, 1999; p. 226).

Propagation:  Bulbils.

Native range:  Tropical South America (Smith, 1985; p. 627).

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 invasive	Orchard, Anthony E., ed. (1994) (p. 20) "A native of South America now widespread as a weed of disturbed ground throughout temperate and warm temperate regions". Vouchers cited: J. Pickard 2676 (NSW), J. Pickard 1214 (NSW), A.C. Beauglehole 5780 (MEL)
Australia (Pacific offshore islands) Norfolk Islands	Norfolk Island	introduced invasive	Orchard, Anthony E., ed. (1994) (p. 10) "A native of South America now widespread as a weed of disturbed ground throughout temperate and warm temperate regions". Vouchers cited: P.S. Green 1364 (A); R.M. Laing (CHR); 1939, J.D. McComish (NSW)
Cook Islands Southern Cook Islands	Mangaia Island		McCormack, Gerald (2008)
Ecuador (Galápagos Islands) Floreana Group	Floreana Island	introduced invasive cultivated	Charles Darwin Foundation (2008) var. corymbosa. As Oxalis corymbosa.
Ecuador (Galápagos Islands) Isabela Group	Isabela Island	introduced invasive cultivated	Charles Darwin Foundation (2008) var. corymbosa. As Oxalis corymbosa.
Ecuador (Galápagos Islands) Isabela Group	Volcán Cerro Azul, Isabela Island	introduced invasive cultivated	Charles Darwin Foundation (2008) var. corymbosa. As Oxalis corymbosa.
Ecuador (Galápagos Islands) Isabela Group	Volcán Sierra Negra, Isabela Island	introduced invasive cultivated	Charles Darwin Foundation (2008) var. corymbosa. As Oxalis corymbosa.
Ecuador (Galápagos Islands) San Cristóbal Group	San Cristóbal Island	introduced invasive cultivated	Charles Darwin Foundation (2008) var. corymbosa. As Oxalis corymbosa.
Ecuador (Galápagos Islands) Santa Cruz Group	Santa Cruz Island	introduced invasive cultivated	Charles Darwin Foundation (2008) var. corymbosa. As Oxalis corymbosa.
Fiji Fiji Islands	Viti Levu Island	introduced invasive cultivated	Smith, Albert C. (1985) (p. 627) Vouchers cited: Greenwood 803, DA 5605, DA 11742, DA 11229, DA 11540, DA 13275
French Polynesia Society Islands	Society Islands	introduced invasive cultivated	Smith, Albert C. (1985) (p. 627)
State of Hawaii Hawaiian Islands	Hawai‘i (Big) Island	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (pp. 1002, 1004, 1887)
State of Hawaii Hawaiian Islands	Kaua‘i Island	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (pp. 1002, 1004, 1887)
State of Hawaii Hawaiian Islands	Lāna‘i Island	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (pp. 1002, 1004, 1887)
State of Hawaii Hawaiian Islands	Maui Island	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (pp. 1002, 1004, 1887)
State of Hawaii Hawaiian Islands	Moloka‘i Island	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (pp. 1002, 1004, 1887)
State of Hawaii Hawaiian Islands	O‘ahu Island	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (pp. 1002, 1004, 1887) Voucher cited: Mann & Brigham 37 (BISH)
Japan (offshore islands) Bonin (Ogasawara) Islands	Bonin (Ogasawara) Islands	introduced invasive	Toyoda, Takeshi (2003) (p. 287) As Oxalis corymbosa DC. Naturalized
Japan (offshore islands) Bonin (Ogasawara) Islands	Bonin (Ogasawara) Islands	introduced	Kato, Hidetoshi (2007) Subsp. corymbosa (DC.) Lourteig
New Caledonia Îles Bélep (Belep Islands)	Île Art	introduced invasive	MacKee, H. S. (1994) (p. 109) Voucher cited: MacKee 19456
New Caledonia New Caledonia	New Caledonia Islands	introduced invasive cultivated	Smith, Albert C. (1985) (p. 627)
New Caledonia New Caledonia	New Caledonia Islands	introduced invasive	Gargominy, Oliver/Bouchet, Philipe/Pascal, Michel/Jaffre, Tanguy/Tourneu, Jean-Christophe (1996) (p. 382) Mauvaise herbe répandue.
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) (p. 109) Vouchers cited: Buchholz 1316, Guillaumin 8463, MacKee 5565, MacKee 11994, MacKee 12878, MacKee 40971
Samoa Western Samoa Islands	Western Samoa Islands	introduced invasive cultivated	Smith, Albert C. (1985) (p. 627)
Vanuatu New Hebrides Islands	Vanuatu (Republic of)		Swarbrick, John T. (1997) (p. 95)

Pacific Rim
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
Colombia Colombia	Colombia (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2009)
Ecuador (Mainland) Ecuador	Ecuador (Republic of) (continental)	native	U.S. Dept. Agr., Agr. Res. Serv. (2009)
Indonesia Indonesia	Indonesia (Republic of)	introduced invasive	Waterhouse, D. F. (1993) (pp. 67, 78)
Malaysia Malaysia	Malaysia (country of)	introduced invasive	Waterhouse, D. F. (1993) (pp. 67, 78)
New Zealand New Zealand	New Zealand (country)	introduced invasive	Webb, C. J./Sykes, W. R./Garnock-Jones, P. J. (1988) (p. 918) "Primarily a weed of cultivated soil, and waste, usually open, disturbed ground".
Perú Perú	Perú (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2009)
Singapore Singapore	Singapore (Republic of)	introduced invasive	Waterhouse, D. F. (1993) (pp. 67, 78)
Thailand Thailand	Thailand (Kingdom of)	introduced invasive	Waterhouse, D. F. (1993) (pp. 67, 78)

Indian Ocean
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
Mauritius Mautitius Islands (Mauritius and Rodrigues)	Mauritius Island		Holm, Leroy/Pancho, Juan V./Herberger, James P./Plucknett, Donald L. (1979) (p. 259)

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

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

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

Other Latin names:  Oxalis corymbosa DC.

References:

Charles Darwin Foundation. 2008. Database inventory of introduced plant species in the rural and urban zones of Galapagos. Charles Darwin Foundation, Galapagos, Ecuador.

Charles Darwin Research Station. 2005. CDRS Herbarium records.

Gargominy, Oliver/Bouchet, Philipe/Pascal, Michel/Jaffre, Tanguy/Tourneu, Jean-Christophe. 1996. Conséquences des introductions d'espèces animales et végétales sur la biodiversité en Nouvelle-Calédonie. Rev. Ecol. (Terre Vie) 51:375-401.

Holm, Leroy/Pancho, Juan V./Herberger, James P./Plucknett, Donald L. 1979. A geographical atlas of world weeds. John Wiley & Sons, New York. 391 pp.

Kato, Hidetoshi. 2007. Herbarium records of Makino Herbarium, Tokyo Metropolitan University. Personal communication.

MacKee, H. S. 1994. Catalogue des plantes introduites et cultivées en Nouvelle-Calédonie. Muséum National d'Histoire Naturelle, Paris, 164 p.

McCormack, Gerald. 2008. Cook Islands Biodiversity Database, Version 2007.2. Cook Islands Natural Heritage Trust, Rarotonga.

McMullen, C. K. 1999. Flowering plants of the Galápagos. Comstock Pub. Assoc., Ithaca, N.Y. 370 p.

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

Smith, Albert C. 1985. Flora Vitiensis nova: a new flora of Fiji. National Tropical Botanical Garden, Lawai, Kauai, Hawaii. Volume 3. 758 pp.

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

Tassin, Jacques. 2005. Jacques Tassin (IAC-CIRAD), personal communication.

Toyoda, Takeshi. 2003. Flora of the Bonin Islands. Aboc & Co. 522 pp.

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.

Wiggins, I. L./Porter, D. M. 1971. Flora of the Galapágos Islands. Stanford University Press. 998 pp.