Oxalis facts for kids

Kids Encyclopedia Facts

Quick facts for kids Oxalis

Oxalis pes-caprae
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Angiosperms
Clade:	Eudicots
Clade:	Rosids
Order:	Oxalidales
Family:	Oxalidaceae
Genus:	*Oxalis* L.
Species
About 550, see List of Oxalis species

Oxalis is a big group of flowering plants, with over 550 different kinds! They are part of the wood-sorrel family, called Oxalidaceae. You can find Oxalis plants almost everywhere in the world, except for the very cold polar areas. Many types grow especially well in warm places like Brazil, Mexico, and South Africa.

Many of these plants are known as wood sorrels. They have a sour taste, a bit like lemons, which reminds people of another plant called sorrel. Some Oxalis plants are called yellow sorrels or pink sorrels because of their flower colors. Others are sometimes called false shamrocks or sourgrasses.

What are Oxalis Plants Like?
How Humans Use Oxalis
- Oxalis as Food
- Oxalic Acid in Oxalis
Oxalis as Garden Plants
Selected Species
Gallery
See also

What are Oxalis Plants Like?

Leaves, Flowers, and Roots

Floral diagram of Oxalis

Oxalis plants can be annuals (meaning they live for one year) or perennials (meaning they live for many years). Their leaves are usually divided into three to ten or more smaller parts. These parts are often shaped like a heart or a teardrop. Most Oxalis plants have three leaf parts, which makes them look a bit like clovers. Some species can quickly change the angle of their leaves. This helps them avoid too much sunlight and stay healthy.

The flowers of Oxalis plants have five petals, which are usually joined at the bottom. They also have ten stamens, which are the parts that make pollen. The petals can be white, pink, red, or yellow. The fruit is a small capsule that holds several seeds. Many Oxalis plants have thick, juicy roots that store energy. Some can also grow new plants from small parts called bulbils that break off.

Where Oxalis Plants Grow

Common wood sorrel (Oxalis acetosella)

Pale grass blue (Pseudozizeeria maha) laying eggs on Oxalis

Several types of Oxalis plants are very common in certain forest areas. For example, in the North American Pacific Northwest and parts of Australia, you might find lots of them. In Europe, the common wood sorrel (O. acetosella) often covers large areas in forests.

Some Oxalis species, like Bermuda-buttercup and creeping woodsorrel, can become invasive weeds. This happens when they escape from gardens and grow out of control in new places. It's hard to get rid of them because their roots can store a lot of energy, making them tough against weed control.

A study in 2019 suggested that Oxalis plants work together with tiny bacteria called Bacillus. These bacteria help the plants get nitrogen from the soil. This might be why Oxalis can spread quickly, even in poor soil.

Oxalis and Animals

Some small plant-eating animals, like the Montezuma quail, eat the roots of Oxalis plants. The leaves are also a food source for certain butterflies, such as the Polyommatini pale grass blue and dark grass blue.

Oxalis plants can sometimes get a plant disease called rust, which is caused by a fungus called Puccinia oxalidis.

How Humans Use Oxalis

Oxalis as Food

Wood sorrel, a type of Oxalis, is a wild plant that people have eaten for thousands of years. Native American groups used it in many ways:

The Kiowa people chewed wood sorrel to help with thirst on long journeys.
The Potawatomi cooked it with sugar to make a dessert.
The Cherokee ate wood sorrel to help with mouth sores and sore throats.
The Iroquois ate wood sorrel to help with cramps, fever, and nausea.

An apricot-coloured variety of Oxalis tuberosa for eating

Some oca

The juicy, edible roots of a type of Oxalis called oca (O. tuberosa) have been grown for food in Colombia and other parts of the Andes mountains in South America for a long time. In New Zealand, oca is sold as "New Zealand yam," even though it's not a true yam. You can find different colors of oca now, like yellow, orange, apricot, and pink.

Sailors traveling around Patagonia used to eat the leaves of scurvy-grass sorrel (O. enneaphylla). It was a good source of vitamin C, which helped them avoid a disease called scurvy.

In India, creeping wood sorrel (O. corniculata) is eaten only at certain times of the year. The Bodos in northeast India sometimes use its leaves to make a sour fish curry. You can also dry the leaves of common wood sorrel (O. acetosella) to make a lemony-tasting tea.

Oxalic Acid in Oxalis

Oxalic acid, a natural substance found in many wood-sorrels and other edible plants

Four-leaved pink-sorrel (O. tetraphylla) grown as a pot plant

Oxalis versicolor (candycane sorrel) grown in New Zealand

One special thing about Oxalis plants is that they contain oxalic acid. This is what gives their leaves and flowers that sour taste. Oxalic acid is also found in many other common foods you might eat, like spinach, broccoli, brussels sprouts, grapefruit, and rhubarb.

Eating very large amounts of oxalic acid can be slightly harmful because it can affect your digestion and kidneys. However, for most people with healthy kidneys, eating Oxalis in normal amounts is usually not a problem. The U.S. National Institutes of Health says that since oxalic acid is in many foods, its effects are usually not a big concern for people who eat a variety of foods.

In the past, people would take out crystals of calcium oxalate from Oxalis plants. They used these crystals to treat diseases or as a "salt of lemon."

Oxalis as Garden Plants

Double-flowered Oxalis compressa

Oxalis triangularis

Many types of Oxalis are grown as pot plants or ornamental plants in gardens because they are pretty. For example, O. versicolor is a popular choice.

Oxalis flowers come in many colors, including white, yellow, peach, pink, and even multi-colored. Some types have double flowers, like the double form of O. compressus. Other varieties are grown for their interesting leaves, such as O. triangularis, which has dark purple leaves.

Some Oxalis species, especially O. tetraphylla (four-leaved pink-sorrel), are sometimes sold as "four-leaf clovers." People buy them hoping for good luck, just like with real four-leaf clovers.

Selected Species

Oxalis acetosella – common wood sorrel, stabwort
Oxalis adenophylla – Chilean oxalis, silver shamrock
Oxalis albicans – hairy woodsorrel, white oxalis, radishroot woodsorrel, radishroot yellow-sorrel, California yellow-sorrel
Oxalis alpina – alpine sorrel
Oxalis ambigua
Oxalis articulata Savign. – pink-sorrel
Oxalis ausensis
Oxalis barrelieri – lavender sorrel
Oxalis bowiei – Bowie's wood-sorrel, Cape shamrock
Oxalis brasiliensis – Brazilian woodsorrel
Oxalis caerulea – blue woodsorrel
Oxalis caprina
Oxalis corniculata – creeping wood sorrel, procumbent yellow-sorrel, sleeping beauty, chichoda bhaji (India)
Oxalis debilis Kunth
Oxalis decaphylla – ten-leaved pink-sorrel, tenleaf wood sorrel
Oxalis dehradunensis
Oxalis depressa
Oxalis dichondrifolia – peonyleaf wood sorrel
Oxalis dillenii Jacquin – southern yellow woodsorrel, Dillen's woodsorrel, Sussex yellow-sorrel
Oxalis drummondii – Drummond's woodsorrel, chevron oxalis
Oxalis ecuadorensis
Oxalis enneaphylla – scurvy-grass sorrel
Oxalis exilis – least yellow-sorrel
Oxalis frutescens – shrubby wood-sorrel
Oxalis gigantea
Oxalis glabra – finger-leaf
Oxalis grandis – great yellow-sorrel, large yellow woodsorrel
Oxalis griffithii Edgew. & Hook.f.
Oxalis hedysaroides – fire fern
Oxalis hirta – hairy sorrel
Oxalis illinoensis – Illinois wood-sorrel
Oxalis inaequalis
Oxalis incarnata L. – pale pink-sorrel
Oxalis lasiandra – Mexican shamrock
Oxalis latifolia Kunth – garden pink-sorrel
Oxalis luederitzii
Oxalis luteola Jacq.
Oxalis magellanica G.Forst.
Oxalis magnifica Kunth – snowdrop wood-sorrel
Oxalis massoniana
Oxalis megalorrhiza – fleshy yellow-sorrel
Oxalis melanosticta
Oxalis micrantha – dwarf woodsorrel
Oxalis montana – mountain woodsorrel, white woodsorrel
Oxalis nelsonii – Nelson's sorrel
Oxalis norlindiana
Oxalis obliquifolia
Oxalis oregana – redwood sorrel, Oregon sorrel
Oxalis ortgiesii Regel – fishtail oxalis
Oxalis pennelliana
Oxalis pes-caprae – Bermuda-buttercup, African wood-sorrel, Bermuda sorrel, buttercup oxalis, Cape sorrel, English weed, soursob, "goat's-foot", "sourgrass", soursop (not to be confused with the fruit of that name)
Oxalis priceae – tufted yellow-sorrel
Oxalis pulchella
Oxalis purpurea L. – purple wood-sorrel
Oxalis rosea Feuillée ex Jacq. – annual pink-sorrel
Oxalis rubra A.St.-Hil. – red wood-sorrel
Oxalis rufescens
Oxalis rugeliana – coamo
Oxalis schaeferi
Oxalis spiralis – spiral sorrel, volcanic sorrel, velvet oxalis
Oxalis stricta – common yellow woodsorrel, common yellow oxalis, upright yellow-sorrel, lemon clover, "pickle plant", "sourgrass, "yellow woodsorrel"
Oxalis suksdorfii – western yellow woodsorrel, western yellow oxalis
Oxalis tenuifolia – thinleaf sorrel
Oxalis tetraphylla – four-leaved pink-sorrel, four-leaf sorrel, Iron Cross oxalis, "lucky clover"
Oxalis triangularis – threeleaf purple shamrock
Oxalis trilliifolia – great oxalis, threeleaf woodsorrel
Oxalis tuberosa – oca, oka, New Zealand yam
Oxalis valdiviensis – Chilean yellow-sorrel
Oxalis virginea – virgin wood-sorrel
Oxalis versicolor – candycane sorrel
Oxalis violacea – violet wood-sorrel
Oxalis vulcanicola – volcanic sorrel or velvet oxalis