Oxalis

Oxalis << OK suh lihs >> is the name of a large group of plants that grow chiefly in South Africa and South America. There are hundreds of species (kinds) of oxalis. Many species grow as weeds. However, gardeners cultivate some species as ornamental plants and grow them in hanging baskets, window gardens, or rock gardens.

Water sorrel, an endangered South African wetland plant
Water sorrel, an endangered South African wetland plant

Most kinds of oxalis grow from bulbs, from rootlike rhizomes, or from thickened underground stems called tubers. They have showy flowers that may be white or a variety of pastel colors. The leaves are shaped somewhat like clover leaves. Both the leaves and flowers close up at night. The leaves taste sour because they contain oxalic acid. The acid is so named because it comes from the oxalis plant. The leaves of some kinds of oxalis can be used in salads. One species of oxalis is cultivated in South America for its edible tubers.