Oxalis L.
  • Sp. Pl. 1: 433. 1753. (1 May 1753)
  • Wood-sorrel, sourgrass, false shamrock [Greek oxys, acid, and -alis, with the nature of, alluding to supposed medicinal use]


Cite taxon page as 'WFO (2021): Oxalis L. Published on the Internet;http://www.worldfloraonline.org/taxon/wfo-4000027521. Accessed on: 23 Sep 2021'

General Information

Herbs, annual or perennial, usually with tubers, bulbs, or rhizomes. Stems erect, creeping, or absent (rosette). Stipules usually absent or very small. Leaves radical or alternate, 3-foliolate (Chinese taxa). Inflorescences solitary, cymose, or umbellate; peduncle long, with 2 small bracts at apex, bracts appearing to be mid peduncle in solitary-flowered species. Sepals distinct, imbricate. Petals yellow, red, pink, or white, convolute, sometimes basally slightly connate. Stamens all fertile; filaments basally connate or distinct. Ovary locules with 1 to several ovules. Capsule loculicidally dehiscent. Seeds with an outer fleshy coat which bursts elastically.

  • Provided by: [C].Flora Of CHina @ efloras.org
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    Herbs [subshrubs, shrubs, or vines], caudex absent (present in O. dichondrifolia, O. frutescens, O. montana, and O. texana), usually with tubers, bulbs, or rhizomes, sometimes fibrous-rooted or taprooted. Aerial stems erect to decumbent, prostrate, or creeping, or absent. Leaves basal or cauline, palmately compound (pinnately compound in O. frutescens, 1-foliolate in O. dichondrifolia); leaflets pulvinate, usually 2-lobed, sometimes not lobed, often deflexed and folded together at night, laminae and margins often with black or orange oxalate dots or stripes. Flowers tristylous, distylous, semihomostylous (one whorl of anthers at level of stigmas, other proximal or distal), or homostylous (all anthers at level of stigmas); petals yellow, white, pink, salmon, red, lavender, purple, or violet; stamens: filaments 5 long and 5 short, alternating with one another, or equal length. x = (5–)7(–12).

  • Provided by: [F].Flora of North America @ efloras.org
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    OXALIS L.; Acetosella Kuntze; Pseudoxalis Rose; Bolboxalis Small; Ionoxalis Small; Hesperoxalis Small; Lotoxalis Small; Monoxalis Small; Otoxalis Small; Xanthoxalis Small.

    Hierbas o subarbustos, anuales o perennes; tallos erectos, postrados o acaulescentes. Hojas alternas o basales, pinnada o palmadamente 3 (–4)-folioladas; estípulas ausentes, o si presentes, connadas a los pecíolos. Flores solitarias o en cimas, axilares, basales, bracteoladas; sépalos y pétalos connados cerca de la mitad; pétalos unguiculados; estambres del verticilo externo cortos, los del verticilo interno largos, filamentos connados en la base; pistilo heterostilo, carpelos 1–15-ovulados, estigmas capitados. Fruto una cápsula loculicida; semillas carnosas, ariladas.

    Género con 500–750 especies de distribución mundial desde regiones templadas frías hasta tropicales; 5 especies se conocen en Nicaragua, incluyendo 1 cultivada.

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    Herbs or subshrubs, rarely lianas; roots branched fibrous or subligneous thickened; stems underground and reduced to an invisible disc covered with bracts and the base of petioles connate to the stipules, or modified in a more or less ligneous, thickened rhizome covered with the base of the decayed leaves, or aerial and climbing, decumbent, trailing or erect, subligneous at the base, or all herbaceous. Leaves alternate, apparently basal or cauline, subopposite or pseu- doverticillate, 3(-4)-foliolate, digitate or pinnate, with or without stipules connate to the petioles. Inflorescences axillary, of 2-branched or umbelliform cymes or solitary flowers; bracteoles 2; bracts small. Flowers varying in size, rarely cleis- togamous; calyx 5-partite; petals 5, connate near the middle; stamens 10, connate at the base, the series of 5 external alternisepalous stamens opposite the petals, shorter, the internal series alternipetalous, longer, usually all fertile; pistils het- erostylous, bi-, trimorphic, the carpels 1-15-ovuled, the styles 5, free, the stigmas capitate. Capsule globose, oblong to cylindric, glabrous or pubescent, the carpels (1-)2-15-seeded, loculicidally dehiscent, the carpels connate to the central axis, persistent; seeds generally ovoid, apiculate or oblong, more or less flattened, the testa crustaceous, longitudinally zig-zag ribbed, transversally striate or sculptured densely verrucate, 2-tegmic, the external integument fleshy, arilliform, breaking elastically and projecting the ripe seeds; albumen fleshy; embryo straight.

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    Morphology

    Flowers actinomorphic, usually heterostylous (homostylous in O. corniculata), solitary or subtended by bracts in pseudumbels or cymes.

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    Petals contorted, unguiculate; claws ± coherent to form a false tube.

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    Stamens 10, 2-seriate, the outer 5 shorter and opposite the petals, the inner 5 longer and opposite the sepals (vestiges of a third whorl sometimes present); filaments usually connate at the base and sometimes with dentate appendages; anthers introrse in bud, dehiscing by slits.

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    Ovary with several ovules in each loculus; ovules anatropous.

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    Capsule loculicidally dehiscent.

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    Seeds with or without endosperm and with a testa which becomes fleshy and eventually everts explosively ejecting the contents.

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    Caulescent or acaulescent annual or perennial herbs, usually bulbous, occasionally suffruticose.

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    Leaves radical or cauline, alternate or often in a cluster, digitately 3-foliolate (in our area) or pinnately 3-foliolate or sometimes 1-foliolate.

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    Sepals sometimes with apical calli

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    Leaves radical or cauline, alternate, digitately or pinnately (1–)3-foliolate, rather sensitive to light and drooping at night, petiolate, sometimes with membranous stipules adnate to the petiole

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    Flowers pedicellate, subtended by bracts, in pseudumbels or cymes or solitary, usually trimorphic heterostylous (largely homostylous in O. corniculata)

  • Provided by: [I].Plants Of the World Online Portal - FTEA
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    Seeds brown, covered by a white fleshy integument, which bursts elastically by contraction expelling the seeds when ripe.

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    Petals contorted in bud, falsely connate near the base

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    Stamens 10,2-seriate, with 5 outer short filaments opposite the petals and 5 inner long filaments opposite the sepals; filaments usually fused at the bottom to form a tube and sometimes the long filaments each with an appendage at the back; anthers opening by slits

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    Caulescent or acaulescent perennial or annual herbs, bulbous or not

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    Ovary of 5 fused carpels, with 1–many ovules in each carpel; stigma terminal, capitate, 2-fid or laciniate

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    Fruit a capsule, with the valves persisting around the central column

  • Provided by: [I].Plants Of the World Online Portal - FTEA
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    Herbes'acaules ou caulescentes, annuelles ou vivaces, souvent à bulbes et rhizomes.'Feuilles'alternes, avec ou sans stipules, digitées 3- à plurifoliolées ou pennées 3-4-foliolées, rarement 1- foliolées, ou transformées en phyllodes; folioles entières ou ± émarginées à bilobées au sommet, parfois munies de callosités.'Inflorescences'axillaires ou caulinaires, en ombelles simples ou composées ou cymes, parfois fleurs solitaires.'Fleurs'jaunes, roses, rouges, violacées ou blanches, parfois cleistogames; bractéoles présentes ou absentes; sépales 5, imbriqués, parfois munis de callosités vers le sommet; pétales 5, tordus; étamines 10, toutes fertiles, ± connées à la base en un anneau, les 5 externes plus petites; anthères basifixes, à déhiscence longitudinale; styles 5, hétéromorphes.'Capsules'loculicides, à valves persistantes, généralement dressées à maturité.'Graines à tégument extérieur charnu, arilliforme se séparant élastiquement.\n\t\t\t\tGenre cosmopolite comprenant ± 700 espèces, surtout d'Amérique et d'Afrique australes, au Congo belge, 7 espèces dont 2 introduites.

  • Provided by: [E].Flore d'Afrique Centrale
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    Habit

    Herbs or subshrubs

  • Provided by: [D].Flora de Panama
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    Distribution

    distributed around the world in tropical and cold regions, from sea level to the snow-line in the highest mountains.

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    Literature

    SELECTED REFERENCES Denton, M. F. 1973. A monograph of Oxalis, section Ionoxalis (Oxalidaceae) in North America. Publ. Mus. Michigan State Univ., Biol. Ser. 4: 455–615. Eiten, G. 1963. Taxonomy and regional variation of Oxalis section Corniculatae. I. Introduction, keys and synopsis of the species. Amer. Midl. Naturalist 69: 257–309. Gardner, A. G. et al. 2012. Diversification of the American bulb-bearing Oxalis (Oxalidaceae): Dispersal to North America and modification of the tristylous breeding system. Amer. J. Bot. 99: 152–164. Lourteig, A. 1975. Oxalidaceae extra-Austroamericanae: 1. Oxalis L. sectio Thamnoxys Planchon. Phytologia 29: 449–471. Lourteig, A. 1979. Oxalidaceae extra-Austroamericanae: 2. Oxalis L. sectio Corniculatae DC. Phytologia 42: 57–198. Lourteig, A. 1982. Oxalidaceae extra-Austroamericanae: 4. Oxalis L. sectio Articulatae Knuth. Phytologia 50: 130–142. Lourteig, A. 1994. Oxalis L. subgénero Thamnoxys (Endl.) Reiche emend. Lourt. Bradea 7: 1–199. Lourteig, A. 2000. Oxalis L. subgeneros Monoxalis (Small) Lourt., Oxalis y Trifidus Lourt. Bradea 7: 201–629. Nesom, G. L. 2009b. Again: Taxonomy of yellow-flowered caulescent Oxalis (Oxalidaceae) in eastern North America. J. Bot. Res. Inst. Texas 3: 727–738. Nesom, G. L. 2009c. Notes on Oxalis sect. Corniculatae (Oxalidaceae) in the southwestern United States. Phytologia 91: 527–533. Nesom, G. L. 2009d. Taxonomic notes on acaulescent Oxalis (Oxalidaceae) in the United States. Phytologia 91: 501–526. Nesom, G. L., D. D. Spaulding, and H. E. Horne. 2014. Further observations on the Oxalis dillenii group (Oxalidaceae). Phytoneuron 2014-12: 1–10. Ornduff, R. 1972. The breakdown of trimorphic incompatibility in Oxalis section Corniculatae. Evolution 26: 52–65. Robertson, K. R. 1975. The Oxalidaceae in the southeastern United States. J. Arnold Arb. 56: 223–239. Rosenfeldt, S. and B. G. Galati. 2009. The structure of the stigma and the style of Oxalis spp. (Oxalidaceae). J. Torrey Bot. Soc. 136: 33–45. Weller, S. G. and M. F. Denton. 1976. Cytogeographic evidence for the evolution of distyly from tristyly in the North American species of Oxalis section Ionoxalis. Amer. J. Bot. 63: 120–125. Wiegand, K. M. 1925. Oxalis corniculata and its relatives in North America. Rhodora 27: 113–124, 133–139.

  • Provided by: [F].Flora of North America @ efloras.org
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    Included Species

    Other Local Names

    NameLanguageCountry
    Wood-sorrel, sourgrass, false shamrock [Greek oxys, acid, and -alis, with the nature of, alluding to supposed medicinal use]

     Information From

    MBG Floras Images
    http://www.tropicos.org/ImageSearch.aspx
    Flora images. Missouri Botanical Garden. Accessed on Jun. 2018.
    • A Missouri Botanical Garden
    • B Missouri Botanical Garden
    Flora Of CHina @ efloras.org
    http://www.efloras.org/flora_page.aspx?flora_id=2
    'Flora of China @ eFloras (2008). Published on the Internet http://www.efloras.org/flora_page.aspx?flora_id=2 [accessed August 2016]' Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.
    • C Missouri Botanical Garden
    Flora de Panama
    http://www.tropicos.org/Project/PAC
    Robert E. Woodson, Jr. and Robert W. Schery Annals of the Missouri Botanical Garden Vol. 67, No. 4 (1980), pp. ii-xxxiii
    • D Missouri Botanical Garden
    Flore d'Afrique Centrale
    https://www.floredafriquecentrale.be
    • E http://creativecommons.org/licenses/by/4.0/ Attribution 4.0 International (CC BY 4.0)
    Flora of North America @ efloras.org
    http://www.efloras.org/flora_page.aspx?flora_id=1
    'Flora of North America @ eFloras (2008). Published on the Internet http://www.efloras.org/flora_page.aspx?flora_id=1 [accessed August 2016]' Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.
    • F Flora of North America Association
    Flora de Nicaragua
    http://www.tropicos.org/projectwebportal.aspx?projectid=7&pagename=Home&langid=66
    WD Stevens, CU Ulloa, A Pool and OM Montiel. Missouri Botanical Garden Press, 2001
    • G Missouri Botanical Garden
    Oxalidaceae
    World Flora Online Data. 2017.
    • H CC0 1.0 Universal (CC0 1.0).
    Plants Of the World Online Portal - FTEA
    https://www.kew.org/science/who-we-are-and-what-we-do/strategic-outputs-2020/plants-of-the-world-online
    http://www.plantsoftheworldonline.org/terms-and-conditions
    • I
    Plants Of the World Online Portal - FZ
    https://www.kew.org/science/who-we-are-and-what-we-do/strategic-outputs-2020/plants-of-the-world-online
    http://www.plantsoftheworldonline.org/terms-and-conditions
    • J
    World Flora Online consortium
    http://www.worldfloraonline.org/organisation/WFO
    World Flora Online Data. 2018.
    • K CC0 1.0 Universal (CC0 1.0).