Oxalis - Sorrel

• Family: Oxalidaceae ^[E-flora]

Habit: Roots fibrous or woody; bulbs, tubers, or rhizomes often present. Stem: +- 0 or not. Leaf: stipules 0 or small; leaflets 3, generally +- obcordate [not], generally entire, generally green. Flower: petals clawed; styles erect or curved. Fruit: cylindric to spheric, explosively dehiscent. Seed: flat, often ridged; aril translucent.
Species In Genus: 500--950 species: especially temperate. Etymology: (Greek: sour, from acidic taste) Note: Taxonomy difficult, needs study; generally heterostylous; many (especially aliens in California except Oxalis micrantha) ornamental; some noxious weeds; oxalates may be TOXIC to livestock; Oxalis latifolia Kunth possibly naturalized in CCo (Keil 30389, just north of San Simeon), differs from Oxalis purpurea in having flowers in umbel-like cyme; Oxalis hirta L. an historical waif (no recent collections), excluded. ^[Jepson]

Local Species;

1. Oxalis acetosella - Common wood sorrel ^[E-flora] (Only shown in Vancouver Area)
2. Oxalis corniculata - Yellow oxalis ^[E-flora]
3. Oxalis oregana - Redwood sorrel ^{[E-flora][PCBC][TSFTK]}
4. Oxalis stricta - Upright yellow oxalis ^[E-flora]

Oxalis oregana - Blue Listed ^[E-flora-3]

Hazards

The leaves of wood-sorrels (Oxalis spp.) contain oxalic acid, giving them a pleasant, sour taste, but should not be consumed in large quantities".^{[Turner&Kuhnlein]} "In spite of many authors claiming so, oxalates are not a problem for normal healthy humans eating a normally diverse diet." ^{[Kallas EWP]}

• O. acetosella, O. corniculata, O. oregana, O. stricta; The leaves contain oxalic acid, which gives them their sharp flavour. Perfectly all right in small quantities, the leaves should not be eaten in large amounts since oxalic acid can bind up the body's supply of calcium leading to nutritional deficiency. The quantity of oxalic acid will be reduced if the leaves are cooked. People with a tendency to rheumatism, arthritis, gout, kidney stones or hyperacidity should take especial caution if including this plant in their diet since it can aggravate their condition[238].^{[PFAF-1,2,3,4]}

To reduce page congestion, I will redirect the reader to the forum thread "Oxalates" for a detailed exposition on Oxalic acid, calcium oxalate and Oxalates in general.

Food

• Sprouts: Oxalis Sp.; Sprouts eaten raw. (124:93) ^{[NAEth Moerman]}
• Aboverground Parts: "The leaves, stems, and flowers can be used in salads". Quite sour. The leaves and stems can be used as a sauerkraut by slightly fermenting them. Stems made into pies. ^[Nyerges] O. acetosella; dried plant used to curdle plant milks.[66] ^[PFAF-4]
• Leaves: ^{[EMP Wildman]} Leaves eaten raw or added to soups.^{[?uczaj,2008]} O. oregana; Leaves - raw or cooked[118, 183, 257]. They can be harvested all year round[K]. ^[PFAF-1] O.stricta; Raw or cooked[46, 61, 105]. ^[PFAF-2] O. corniculata; raw or cooked[2, 46, 61, 105].^[PFAF-3] O. acetosella; raw or cooked[2, 7, 12, 37]. ^[PFAF-4]
• Flowers: O. acetosella; raw[K]. ^[PFAF-4] O.oregana; Raw. Pleasantly acidic. [K]^[PFAF-1] O.stricta; raw[105, 161, 183].^[PFAF-2] O. corniculata; Raw.[K]^[PFAF-3]
• Young seedpods O.stricta; raw[183]. ^[PFAF-2]
• Root O.stricta; [105, 161, 183]. ^[PFAF-2]

Further Investigations;

Several species with edible tuberous roots are cultivated in Mexico and South America. ^[Nyerges] The larger roots and bulbs of O. tuberosa and O. tetraphylla of South America, and O. deppei of Southern North America and Mexico, have been eaten. ^[PFAF-5] The American species, Oxalis montana, also has "onion-like tubers which can be eaten either raw or cooked." ^{[WildFoodsForum]} It is possible that any species with substantial or plentiful roots could be eaten as a food source. ^{[Personal Note]}

Other Uses

• Cleaning Agent: "Wood sorrel's oxalic acid has been used for removing ink stains and cleaning brass".^[Nyerges]
  • O. acetosella The juice of the leaves removes iron mould stains from linen[6, 66, 115].^[PFAF-4]
• Ethnoveterinary: The pounded bulbs of O. stricta and O. violacea were fed to horses to make them fleet.[143] ^{[Lans et al.]} O. acetosella used for "Ticks and lice in sheep".^[MPFT]
• Dye
  • O. stricta; Dye "called a tan or buckskin color and the whole plant is boiled to get the color."^{[HuronSmith Winnebago]}
  • O. corniculata; Yellow, orange and red to brown dyes are obtained from the flowers[168]. The boiled whole plant yields a yellow dye[257].^[PFAF-3]

Medicinal Uses

• Plant:
  • Decoction
    • O. oregana; A decoction of the whole plant has been used as a wash in the treatment of rheumatism [257]. The fresh juice of the plant has been used as eye drops to ease sore eyes[257]. ^[PFAF-1]
  • Infusion
    • O. corniculata; An infusion can be used as a wash to rid children of hookworms[257].^[PFAF-3]
    • O. oregana; An infusion is used "to cool, as a diuretic, and an astringent". It is said to have stronger blood cleansing abilities than the similarly used sheep sorrel [Rumex acetosella].^[Ward,1936]
    • O.stricta; An infusion of the plant has been used in the treatment of fevers, stomach cramps and nausea[257].^[PFAF-2]
  • Juice
    • O. acetosella; Commonly cited for treatment of cancer of the breast, lip, liver, mouth, spleen, and stomach. The juice is evaporated in the sun, red clover leaf/flower juice added, and then thickened with white oak ashes. It is applied topically (CEB).^{[HMH Duke]}
    • O. corniculata; The juice of the plant, mixed with butter, is applied to muscular swellings, boils and pimples[272]. ^[PFAF-3]
  • Poultice
    • Oxalis Sp.; The leaves have been used as an antiseptic poultice, or wash, for wounds, burns and insect bites. ^{[Tozer UWP]}
    • O.stricta; A poultice of the plant has been used to treat swellings[257].^[PFAF-2]
• Leaves:
  • Antidote
    • O. corniculata; "...to poisoning by the seeds of Datura spp., arsenic and mercury[218]." ^[PFAF-3] O. acetosella; Antidote to arsenic and quicksilver.^{[HMH Duke]}
  • Decoction
    • O. acetosella; A decoction is used in the treatment of fevers, both to quench the thirst and allay the fever[4]. ^[PFAF-4]
  • Juice
    • O. corniculata; The leaf juice is applied to insect bites, burns and skin eruptions[218]. ^[PFAF-3]
  • Poultice
    • O. acetosella; Externally, the leaves are crushed and applied locally to dispel boils and abscesses, they also have an astringent affect on wounds[7].^[PFAF-4]

Description

O. acetosella: European perennial herb much like Oxalis oregana, this species is established in a few places in shady coniferous woods on the north shore of Burrard Inlet, Greater Vancouver. It is an understorey dominant in the forests of the Capilano River. Probably originating from garden dumpings. (Lomer 91-54 @ UBC)^[E-flora-1]

General
O. acetosella: Carpeting old, undisturbed woodlands in spring, this pretty downy perennial also grows on moss-covered trees and shady walls [WFI]
O. oregana; 2-12"^[PSW]
O. corniculata; 1-12"^[PSW] Plant maroon to green. ^[WildPNW] Perennial herb from a slender taproot; stems decumbent to ascending, simple, many, rough hairy, trailing ones freely rooting, herbage brownish to reddish-purple, 5-10 cm tall/long. ^{[IFBC-E-flora2]}
O. stricta; Perennial herb from a slender rhizome; stems erect, sometimes prostrate and matted, simple, few to several, smooth or hairy, 10-50 cm tall/long. ^{[IFBC-E-flora4]}
Lifecycle Wood sorrels (O. stricta) are annuals but will struggle and survive into perennial-ness in very moderate winter climates. ^{[Kallas EWP]}
Flowers Oxalis sp.; White, yellow, red, or pink. 10 stamens, with 5 sepals and 5 petals often united in a spiral twist. The flowers of some species are purplish veined. ^[Nyerges] Oxalis Sp.; calyx five-lobed; the five petals separate ^[PWOBC]
O. acetosella: white five-petalled bell-shaped flower (10 - 15 mm) is held solitarily on a stem which comes directly from the roots. ^[WFI]
O. corniculata; Cluster of 2-7 flowers, deep yellow petals up to 1/4 in. ^[WildPNW]
O. oregana; solitary pink upright funnel-like flowers. ^[PSW]
O. stricta; "peduncles up to 7 -flowered; petals 4-9 mm. long, yellow" ^[HNW]
Fruits Oxalis sp.; A narrow, linear, five-celled pod. ^[Nyerges]
O. corniculata;capsules oblong, 6-25 mm.long, pubescent. ^[HNW]'
Leaves Oxalis sp.; Trifoliate (three leaflets), each leaflet heart shaped with a midrib or midfold. Leaflets unfold in sunshine and retract during cloudy weather and at night.^[Nyerges] "[leaflets] at the tip of the petiole." ^[PWOBC] leaves basal and alternate ^[HNW]
Stem "The green flower stems are stout and succulent". Conspicuous long stems (up to about eight inches tall) ^[Nyerges]
O. corniculata; Slender creeping stems rooting at nodes. ^[PSW]'
O. stricta; "stems prostrate to erect."^[HNW]
Root Oxalis Sp.; fleshy underground rhizomes ^[PWOBC]
O. corniculata; Deep fleshy taproot.^[WildPNW]

Habitat/Range:
O. corniculata: Mesic fields and waste places in the lowland zone; frequent on S Vancouver Island, the Gulf Islands and adjacent coast; introduced from Eurasia. ^{[IFBC-E-flora-2]}
O. oregana: Moist forests in the lowland zone; rare on the Queen Charlotte Islands and W coast of Vancouver Island; S to CA. Native ^{[IFBC-E-flora-3]}
O. stricta: Moist disturbed areas and ditches in the lowland zone; rare in the lower Fraser Valley; introduced from the U.S. ^[E-flora-4]

Status:
O. acetosella: Exotic ^[E-flora-1]
O. corniculata Exotic ^[E-flora-2]
O. oregana Native ^[E-flora-3]
O. stricta Exotic ^[E-flora-4]

Similar Species Wood sorrel leaflets are heart-shaped; and clover are typically not heart-shaped, but "...tend to be round, egg-shaped, or oblong." ^{[Kallas EWP]} Nardoo (Marsilea drummondii), a native of Australia, also toxic and also edible, looks like Oxalis but has 4 leaves. It most certainly doesn't grow in the Pacific Northwest of North America and, from what I've read, only grows in Australia and Tasmania. The difference between Sorrel and the species I mentioned is clear with a simple taste test. Sorrel is lemon-sour from it's oxalic acid content.^{[Personal Note]}

Ethnobotany

Medicinal Uses
Wood Sorrel (Oxalis acetosella) - Throughout Europe ^[PDR]

• Part Used: Fresh flowering plant, including root.^[PDR]
  
• Historical uses include liver and digestive disorders. The fresh leaves were used as an antiscorbutic, and to treat wounds and inflammation of the gums.^[PDR]
• Commonly cited activities include; Diuretic; Emmenagogue; Hemostat; and Toxic (f;EFS).^{[HMH Duke]}
  
• Commonly cited indications include; Bleeding; Catarrh; Dysuria; Fever; Gonorrhea; Hepatosis; Jaundice; Nephrosis; Water Retention; Worms; Wounds.^{[HMH Duke]}
  
• "Other indigenous species of oxalis possess similar properties to O. Acetosella."^{[Remington USD20]}

O. corniculata; It is used in the treatment of influenza, fever, urinary tract infections, enteritis, diarrhoea, traumatic injuries, sprains and poisonous snake bites[147]. ^[PFAF-3]

Nutritional

O. corniculata; Per 100g (fresh weight), crude fiber 0.9g, 86g water. ^{[Turner&Kuhnlein]} 6050µg beta carotene.[173]^[PFAF-3]

Pharmacology

• Oxalis Sp.
  • Alterative: Sprouts used as an alterative. (124:93) ^{[NAEth Moerman]}
• Whole plant
  • O. acetosella; Emmenagogue. ^{[Brinker TBM]}
  • O. corniculata; Anthelmintic, antiphlogistic, antiscorbutic, astringent, depurative, diuretic, emmenagogue, febrifuge, lithontripic, stomachic and styptic[147, 178, 218, 240].^[PFAF-3] "It is sour and useful in the aggravation of vayu as well as kapha. It is hot, astringent, sweet and digestive stimulant." ^[Dash,1980]
• Leaves
  • O. acetosella; The fresh or dried leaves are anodyne, antiscorbutic, astringent, diuretic, emmenagogue, expectorant, febrifuge, irritant and stomachic[4, 7, 9, 21].^[PFAF-4]
  • Leaf Juice
    • O. corniculata; Antibacterial. ^[PFAF-3]

Phytochemistry

• Oxalic Acid - The closely related O. acetosella had an oxalic acid concentration of (0.3-1.25%) and was especially present as potassium salt.^[PDR] (0 corniculata contains up to 7% dry weight of oxalic acid) ^{[Tozer UWP]}

Cultivation

• The leaves can be gathered year-round. ^{[Nyerges] []}
• Groundcover: O. acetosella; Plants can be grown as a ground cover in woodland or under the shade of shrubs[208]^[PFAF-4]
• Oxalis Sp.; They are easily grown from seed or division, in rich moist soil.^{[Tozer UWP]}

Uses of Other Related Sp

Drummond's Woodsorrel (Oxalis drummondii) Decoction of bulb is analgesic. Poultice of bulbs, alone or in compound, applied to sores.^{[NAEth Moerman]}

Wood Sorrel (Oxalis montana): All parts can be eaten. The whole plant used as a lemon flavoring^{[WildFoodForum]} whole plant boiled to yield a yellow dye. ^{[NAEth Moerman]}

Violet Woodsorrel (Oxalis violacea)

• Food Use:
  • Mixed with other leaves and cooked or eaten raw. Bulbs eaten raw or boiled. Leaves, flowers, scapes, and bulbs used for food by children.^{[NAEth Moerman]}
• Medicinal Use
  • Infusion taken and used as an anthelmintic wash for children with hookworms.^{[NAEth Moerman]}
  • Cancer Treatment Used for cancer "when it is first started." ^{[NAEth Moerman]}
• Internal Use
  
  • Infusion
    • Cold infusion of leaf taken to stop vomiting. ^{[NAEth Moerman]}
    • Blood Medicine Infusion taken for blood. ^{[NAEth Moerman]} Oxalis Sp. purify the blood due to their vitamin c content. ^{[Tozer UWP]}
  • Leaves chewed for "disordered saliva" and sore mouth and throat. ^{[NAEth Moerman]}
• External Use
  
  • Dermatological Aid Salve of infusion of leaf mixed with sheep grease used for sores. ^{[NAEth Moerman]}

References

• Dash,1980 - MATERIA MEDICA OF AYURVEDA BASED ON AYURVEDA SAUKHYAM OF TODARANANDA Vaidya Bhagwan Dash, Concept Publishing Company, New Delhi, India, 1980
• E-flora
  • 1 - http://linnet.geog.ubc.ca/Atlas/Atlas.aspx?sciname=Oxalis%20acetosella&redblue=Both&lifeform=7, Accessed July 6, 2015
  • 2 - http://linnet.geog.ubc.ca/Atlas/Atlas.aspx?sciname=Oxalis%20corniculata&redblue=Both&lifeform=7, Accessed July 6, 2015
  • 3 - Oxalis oregana, http://linnet.geog.ubc.ca/Atlas/Atlas.aspx?sciname=Oxalis%20oregana&redblue=Both&lifeform=7, Accessed Aug 27, 2016
  • 4 - Oxalis stricta, http://linnet.geog.ubc.ca/Atlas/Atlas.aspx?sciname=Oxalis%20stricta&redblue=Both&lifeform=7, Accessed Aug 27, 2016
• [Jepson] Robert E. Preston & Robert Ornduff 2016. Oxalis, in Jepson Flora Project (eds.) Jepson eFlora, http://ucjeps.berkeley.edu/cgi-bin/get_IJM.pl?tid=9924, accessed on August 27, 2016.
• Lans et al. - Ethnoveterinary medicines used for horses in Trinidad and in British Columbia, Canada, Cheryl Lans, Nancy Turner, Gerhard Brauer, Grant Lourenco and Karla Georges, Journal of Ethnobiology and Ethnomedicine 2006, 2:31 doi:10.1186/1746-4269-2-31, This article is available from: http://www.ethnobiomed.com/content/2/1/31 (Open Access)
• ?uczaj,2008 - Archival data on wild food plants used in Poland in 1948, ?ukasz ?uczaj, Journal of Ethnobiology and Ethnomedicine 2008, 4:4 doi:10.1186/1746-4269-4-4 http://www.ethnobiomed.com/content/4/1/4 (Open Access)
  • Oxalis spp. including O. acetosella and O. stricta
• Nyerges
  • With reference to Wood Sorrel (Oxalis spp.) ^Nyerges
• PFAF - Accessed July 5, 2015
  • 1 - http://www.pfaf.org/user/Plant.aspx?LatinName=Oxalis+oregana
  • 2 - http://www.pfaf.org/user/Plant.aspx?LatinName=Oxalis+stricta
  • 3 - http://www.pfaf.org/user/Plant.aspx?LatinName=Oxalis+corniculata
  • 4 - http://www.pfaf.org/user/Plant.aspx?LatinName=Oxalis+acetosella
  • 5 - Search of Oxalis sp.
• Tozer UWP
  • Note: Species mentioned; Oxalis sp., with specific mention of O. corniculata, O. violacea, and O. tuberosa
• Ward,1936 - HERBAL MANUAL - The Medicinal, Toilet, Culinary and other Uses of 130 of the most Commonly Used Herbs, HAROLD WARD, 1936 L. N. Fowler & Co. Ltd. 15 New Bridge Street London, U.K., obtained from The Southwest School of Botanical Medicine, http://www.swsbm.com
• [WFI] Wood-sorrel, Wildflowers of Ireland, http://www.wildflowersofireland.net/plant_detail.php?id_flower=243, Accessed Aug 27, 2016

1st search completed. Needs new journal artices. Sources. Is nutritional table from Turner/Kuhnlein????