Oxalis

Revision as of 03:05, 3 May 2025 by imported>Citation bot (Added bibcode. | Use this bot. Report bugs. | Suggested by Awkwafaba | Linked from User:Pengo/missing_plants | #UCB_webform_linked 1277/1925)
(diff) ← Previous revision | Latest revision (diff) | Newer revision → (diff)

Template:Short description {{#invoke:other uses|otheruses}} Template:Automatic taxobox

Oxalis (Template:IPAc-en (American English)<ref>Sunset Western Garden Book, 1995:606–607</ref> or Template:IPAc-en (British English))<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> is a large genus of flowering plants in the wood-sorrel family, Oxalidaceae, comprising over 550 species.<ref name="Christenhusz-Byng2016">Template:Cite journal</ref> The genus occurs throughout most of the world, except for the polar areas; species diversity is particularly rich in tropical Brazil, Mexico, and South Africa.

Many of the species are known as wood sorrels (sometimes written "woodsorrels" or "wood-sorrels") as they have an acidic taste reminiscent of the sorrel proper (Rumex acetosa), which is not closely related. Some species are called yellow sorrels or pink sorrels after the color of their flowers instead. Other species are colloquially known as false shamrocks, and some called sourgrasses. For the genus as a whole, the term oxalises is also used.

DescriptionEdit

The plants are annual or perennial. The leaves are divided into three to ten or more obovate and top-notched leaflets, arranged palmately with all the leaflets of roughly equal size. The majority of species have three leaflets, superficially similar to those of some clovers.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> Some species exhibit rapid changes in leaf angle in response to temporarily high light intensity to decrease photoinhibition.<ref>Template:Cite journal</ref>

The flowers have five petals, which are usually fused at the base, and ten stamens. The petal color varies from white to pink, red or yellow;<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> anthocyanins and xanthophylls may be present or absent but are generally not both present together in significant quantities, meaning that few wood-sorrels have bright orange flowers. The fruit is a small capsule containing several seeds. The roots are often tuberous and succulent, and several species also reproduce vegetatively by production of bulbils, which detach to produce new plants.

EcologyEdit

File:Lyc oviposit.jpg
Pale grass blue (Pseudozizeeria maha) of the dry-season brood laying eggs on Oxalis

Several Oxalis species dominate the plant life in local woodland ecosystems, be it Coast Range ecoregion of the North American Pacific Northwest, or the Sydney Turpentine-Ironbark Forest in southeastern Australia where least yellow sorrel (O. exilis) is common. In the United Kingdom and neighboring Europe, common wood sorrel (O. acetosella) is the typical woodland member of this genus, forming large swaths in the typical mixed deciduous forests dominated by downy birch (Betula pubescens) and sessile oak (Quercus petraea), by sycamore maple (Acer pseudoplatanus), common bracken (Pteridium aquilinum), pedunculate oak (Q. robur) and blackberries (Rubus fruticosus agg.), or by common ash (Fraxinus excelsior), dog's mercury (Mercurialis perennis) and European rowan (Sorbus aucuparia); it is also common in woods of common juniper (Juniperus communis ssp. communis). Some species – notably Bermuda-buttercup (O. pes-caprae) and creeping woodsorrel (O. corniculata) – are pernicious, invasive weeds when escaping from cultivation outside their native ranges; the ability of most wood-sorrels to store reserve energy in their tubers makes them quite resistant to most weed control techniques.

A 2019 study<ref>Template:Cite journal</ref> suggested that species from this genus have a symbiotic relationship with nitrogen fixing Bacillus endophytes, storing them in plant tissues and seeds, which could explain its ability to spread rapidly even in poor soils.

Tuberous woodsorrels provide food for certain small herbivores – such as the Montezuma quail (Cyrtonyx montezumae). The foliage is eaten by some Lepidoptera, such as the Polyommatini pale grass blue (Pseudozizeeria maha) – which feeds on creeping wood sorrel and others – and dark grass blue (Zizeeria lysimon).

Oxalis species are susceptible to rust (Puccinia oxalidis).

File:Close-up of an 'apricot' NZ yam.JPG
An apricot-coloured variety of Oxalis tuberosa for eating

UsesEdit

As foodEdit

Wood sorrel (a type of oxalis) is an edible wild plant that has been consumed by humans around the world for millennia.<ref name="autogenerated2">Template:Cite book</ref> In Dr. James Duke's Handbook of Edible Weeds, he notes that the Native American Kiowa people chewed wood sorrel to alleviate thirst on long trips, the Potawatomi cooked it with sugar to make a dessert, the Algonquin considered it an aphrodisiac, the Cherokee ate wood sorrel to alleviate mouth sores and a sore throat, and the Iroquois ate wood sorrel to help with cramps, fever and nausea.<ref name="autogenerated2" />

The fleshy, juicy edible tubers of the oca (O. tuberosa) have long been cultivated for food in Colombia and elsewhere in the northern Andes mountains of South America. It is grown and sold in New Zealand as "New Zealand yam" (although not a true yam), and varieties are now available in yellow, orange, apricot, and pink, as well as the traditional red-orange.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>

The leaves of scurvy-grass sorrel (O. enneaphylla) were eaten by sailors travelling around Patagonia as a source of vitamin C to avoid scurvy.

In India, creeping wood sorrel (O. corniculata) is eaten only seasonally, starting in December–January. The Bodos of north east India sometimes prepare a sour fish curry with its leaves. The leaves of common wood sorrel (O. acetosella) may be used to make a lemony-tasting tea when dried.

Other usesEdit

In the past, it was a practice to extract crystals of calcium oxalate for use in treating diseases and as a salt called sal acetosella or "sorrel salt" (also known as "salt of lemon"). Growing oca tuber root caps are covered in a fluorescent slush rich in harmaline and harmine which apparently suppresses pests.<ref>Bais et al. (2002, 2003)</ref> Creeping wood sorrel and perhaps other species are apparently hyperaccumulators of copper. The Ming Dynasty text Precious Secrets of the Realm of the King of Xin from 1421 describes how O. corniculata can be used to locate copper deposits as well as for geobotanical prospecting. It thus ought to have some potential for phytoremediation of contaminated soils.Template:Citation needed

As ornamental plantsEdit

Several species are grown as pot plants or as ornamental plants in gardens, for example, O. versicolor.

Oxalis flowers range in colour from whites to yellow, peaches, pink, or multi-coloured flowers.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>

Some varieties have double flowers, for example the double form of O. compressus. Some varieties are grown for their foliage, such as the dark purple-leaved O. triangularis.

Species with four regular leaflets – in particular O. tetraphylla (four-leaved pink-sorrel) – are sometimes misleadingly sold as "four-leaf clover", taking advantage of the mystical status of four-leaf clover.

Selected speciesEdit

{{#invoke:Labelled list hatnote|labelledList|Main article|Main articles|Main page|Main pages}}

File:Oxalis arborea1.jpg
Oxalis articulata Savign. forma crassipes (Urb.) Lourteig, 1982
File:(MHNT) Oxalis articulata - Habit.jpg
Oxalis articulata Savign. subspecies rubra (A.St.-Hil.)
File:Oxalis corymbosa 2.jpg
Oxalis debilis Kunth varietas corymbosa (DC.) Lourteig, 1981

|CitationClass=web }}</ref><ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>

ReferencesEdit

Template:Reflist

Further readingEdit

  • Bais, Harsh Pal; Vepachedu, Ramarao & Vivanco, Jorge M. (2003): Root specific elicitation and exudation of fluorescent β-carbolines in transformed root cultures of Oxalis tuberosa. Plant Physiology and Biochemistry 41(4): 345–353. {{#invoke:doi|main}} Preprint PDF fulltext
  • Łuczaj, Łukasz (2008): Archival data on wild food plants used in Poland in 1948. Journal of Ethnobiology and Ethnomedicine 4: 4. {{#invoke:doi|main}} PDF fulltext

Template:Taxonbar Template:Authority control