T.E.R:R.A.I.N - Taranaki Educational Resource: Research, Analysis and Information Network

Oxalis stricta (Yellow woodsorrel)

Kingdom: Plantae
(Unranked): Angiosperms
(Unranked): Eudicots
(Unranked): Rosids
Order: Oxalidales
Family: Oxalidaceae
Genus: Oxalis
Species: O. stricta
Binomial name: Oxalis stricta
Common names: Common Yellow Woodsorrel (or simply yellow woodsorrel), common yellow oxalis, upright yellow-sorrel, lemon clover, pickle plant.

Oxalis stricta is a herbaceous plant native to North America, parts of Eurasia. It tends to grow in woodlands, meadows, and in disturbed areas as both a perennial and annual. Erect when young, this plant later becomes decumbent as it lies down, and branches regularly. It is not to be confused with similar plants which are also often referred to as "yellow woodsorrel".
Commonly it is considered a weed of gardens, fields, and lawns. It grows in full sun or shade. The alternate leaves of this plant are divided into three heart-shaped leaflets (a typical trait of other species of Oxalis) that can grow up to 2 cm wide. These leaves curl up at night (exhibiting nyctinasty), and open in the day to perform photosynthesis. Occasionally, they fold up in response to intense sunlight during midday.
The yellow flowers of the plant are hermaphroditic and can have patches of red in the throat.
The mature seed capsules open explosively when disturbed (a very similar trait to that of the mature seed capsules or fruits of plants found in the genus Impatiens) and can disperse seeds up to 4 meters away.
Oxalis stricta generally requires dry or moist, alkaline soils, preferring sandy and loamy dirt to grow in. It requires well-drained soil and can grow in nutritionally poor grounds. It does not do well in shade.
Fresh leaves can make a delicious salad or beverage. Wood sorrel is very high in vitamin C.

Thanks to Wikipedia for text and information http://creativecommons.org/licenses/by-sa/3.0/