| Wood-sorrel | |
|---|---|
 | |
Scientific classification | |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Eudicots |
| Clade: | Rosids |
| Order: | Oxalidales |
| Family: | Oxalidaceae |
| Genus: | Oxalis |
| Species: | O. acetosella |
| Binomial name | |
| Oxalis acetosella | |
Oxalis acetosella, thewood-sorrel orcommon wood-sorrel, is a herbaceousrhizomatous flowering plant in the familyOxalidaceae. Thespecific epithetacetosella refers to its sour taste. The common namewood-sorrel is often used for other plants in the genusOxalis.
In much of its range, most of Europe and parts of Asia, it is the only member of its genus and hence simply known as wood-sorrel.[1][2] While 'common wood-sorrel' may be used to differentiate it from most other species, this name is also used for the North AmericanOxalis montana.
The plant grows up to 10 centimetres (4 in) tall.[3] It has trifoliate compoundleaves, the leaflets heart-shaped and folded through the middle, that occur in groups of three on the long petioles, and are finely pubescent. Theflowers are produced singly on thin, wiry stems from spring to midsummer; they are small, open-faced, with five petals 8–15 mm long, which are white with pink or reddish venation.[2] The flowers rarely appear reddish ormauve.[4]: 116 During the night or when it rains, the flowers close and the leaves fold.
Anemonoides nemorosa (wood anemone) is similar. Both have white flowers, are small, and are found in woody shady places.Anemonoides nemorosa however has palmately lobed leaves and does not have true petals but large sepals which are petal-like.[5]
It grows in woods and shady places across most ofEurope and northern and centralAsia.[6] It is commonly found throughout Great Britain and Ireland, except forThe Fens where it is rare.[1][7] It occurs on a wide range of moist soils, both lime-rich and acidic, in Britain from sea level up to 1,160 m in central Scotland (and higher in southern Europe and Asia); it is also tolerant of deep shade, including even dense young conifer plantations.[1] It formerly also occurred inAlgeria in North Africa, but is nowextinct there.[6]
As with other species of wood-sorrel, the leaves are sometimes eaten by humans, but are high inoxalic acid.[3] Anoxalate called "sal acetosella" was formerly extracted from the plant by boiling it.
The common wood-sorrel is sometimes referred to as ashamrock and may be given as a gift onSaint Patrick's Day. This may have began in 1830, when an English botanist James Bicheno claimed wood sorrel to be true shamrock, due to its prettier trifoliateclover-like leaf, its early flowering in March, and because it can be eaten.[8] Despite this, it is more generally accepted that the plant described as "true" shamrock is a species of clover, usually lesser clover (Trifolium dubium).
Wood-sorrel is also known asAlleluia because it blossoms betweenEaster andPentecost, when thePsalms which end withHallelujah are sung.[citation needed]
