Oxalis is a large genus of flowering plants in the wood-sorrel family Oxalidaceae, comprising over 550 species. 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.
Sourgrass is a common name given to several plant species which have a sour taste. Most are in fact not grasses:
Raphanus raphanistrum, also known as wild radish, white charlock or jointed charlock, is a flowering plant in the family Brassicaceae. The species is native to western Asia, Europe and parts of Northern Africa. It has been introduced into most parts of the world and is regarded as a habitat threatening invasive species in many areas, for example, Australia. It spreads rapidly and is often found growing on roadsides or in other places where the ground has been disturbed. The cultivated radish, widely used as a root vegetable, is sometimes considered to be one of its subspecies as Raphanus raphanistrum subsp. sativus.
Trifolium campestre, commonly known as hop trefoil, field clover and low hop clover, is a species of flowering plant native to Europe and western Asia, growing in dry, sandy grassland habitats, fields, woodland margins, roadsides, wastelands and cultivated land. The species name campestre means "of the fields".
Oxalis pes-caprae is a species of tristylous yellow-flowering plant in the wood sorrel family Oxalidaceae. Oxalis cernua is a less common synonym for this species. Some of the most common names for the plant reference its sour taste owing to oxalic acid present in its tissues. Indigenous to South Africa, the plant has become a pest plant in different parts of the world that is difficult to eradicate because of how it propagates through underground bulbs.
Yellow woodsorrel may refer to any member of the woodsorrel genus (Oxalis) with yellow flowers, but especially:
Oxalis stricta, called the common yellow woodsorrel, common yellow oxalis, upright yellow-sorrel, lemon clover, or more ambiguously and informally "sourgrass", "sheep weed", or "pickle plant", is a herbaceous plant native to North America, parts of Eurasia, and a rare introduction in Britain. 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 in the same genus which are also often referred to as "yellow woodsorrel".
Oxalis bowiei, Bowie's wood-sorrel, red-flower woodsorrel, or Cape shamrock, is a plant from the genus Oxalis, which is native to what was Cape Province and KwaZulu-Natal in South Africa. It has also been naturalized in Australia.
Oxalis triangularis, commonly called false shamrock, is a species of perennial plant in the family Oxalidaceae. It is native to several countries in southern South America. This woodsorrel is typically grown as a houseplant but can be grown outside in USDA climate zones 8a–11, preferably in light shade.
Oxalis incarnata is a species of flowering plant in the woodsorrel family known by the common names pale pink-sorrel and crimson woodsorrel. It is native to southern Africa, but it can be found on other continents where it is an introduced species, often the descendant of garden escapees. It is grown and kept as an ornamental plant. This is a perennial herb growing from a system of rhizomes and bulbs. The branching, hairless stem grows to nearly 30 centimeters in maximum length. There may be small bulblets located along the stem above ground. The leaves are borne on long petioles in erect bunches, each leaf made up of three leaflets. The solitary flower arises on a peduncle. Each flower has five white to light pink petals.
Oxalis latifolia is a species of flowering plant in the woodsorrel family known by the common names garden pink-sorrel and broadleaf woodsorrel. It is native to Mexico and parts of Central and South America.
Oxalis montana is a species of flowering plant in the family Oxalidaceae known by the common names mountain woodsorrel, wood shamrock, sours and white woodsorrel. It may also be called common woodsorrel, though this name also applies to its close relative, Oxalis acetosella.
Oxalis articulata, known as pink-sorrel, pink wood sorrel, windowbox wood-sorrel, Chari amilo (Nepal), sourgrass, Netho (khatta) saag (India) is a perennial plant species in the genus Oxalis native to temperate South America. It has been introduced in Europe in gardens and is now naturalized in these areas.
Oxalis debilis, the large-flowered pink-sorrel or pink woodsorrel, is a perennial plant and herb in the family Oxalidaceae. Its original distribution is South America but has become a very cosmopolitan species, occurring in all continents except Antarctica. It can be found in both temperate and tropical areas.
Oxalis priceae, the tufted yellow woodsorrel, is a species of flowering plant in the woodsorrel family. It is native primarily to southeastern North America, with a disjunct population being known from montane areas of Nuevo León, Mexico. This species is found in dry, rocky, calcareous areas such as cedar glades and cliff faces, but it is occasionally found in oak-pine woodlands and longleaf pine savanna as well.
Oxalis illinoensis, the Illinois woodsorrel, is a species of flowering plant in the woodsorrel family (Oxalidaceae). It is endemic to the United States, where it found in Illinois, Indiana, Kentucky, and Tennessee. The limits of the range of this species are unclear due to its similarity to Oxalis grandis, with which there has been confusion.
Oxalis dillenii, the southern wood-sorrel, slender yellow woodsorrel, or Dillen's oxalis, is a species in the woodsorrel family. Like other Oxalis species, the leaves of this plant resemble clover leaves, with three leaflets. The flowers have five yellow petals that are 4 to 10 mm in length. The leaflets are 1 to 2 cm wide with pointed hairs. The fruits are rather brown and are 1.5 to 2.5 cm. It is often considered a weed, and can be found worldwide, but likely originated in North America.
Oxalis exilis, the least yellow sorrel or shady woodsorrel, is a small herbaceous plant found in Australia and New Zealand. It is mainly found in hillsides and weedy areas. It is the smallest species of Oxalis in New Zealand. The colors of the leaves range from green to purple. The capsule and style length vary from 4–6.5 mm.
Oxalis alpina is a herbaceous perennial plant also known by its common name alpine woodsorrel. It is a species belonging to the genus Oxalis.O. alpina is found in North America and Central America from Guatemala to the southwestern United States.
