Shamrock plants that you see in your local grocery store and garden centers are actually wood sorrel, oxalis, plants that grow from bulbs with leaves that grow in groups of three. Inexperienced houseplant growers will mistake the plant's dormancy for a dead plant, but like any other bulb plant, oxalis foliage dies back for the winter months and sprouts again in the spring. Oxalis is native to South America and South Africa. With hundreds of oxalis species, and flowers in colors including white, pink, red, purple, orange and yellow, there's a shamrock plant for every gardener and houseplant enthusiast.
Oxalis Acetosella, Common Wood Sorrel
Oxalis acetosella is also called common wood sorrel and sours because of its taste. It is native to Europe and Asia. It has heart-shaped leaves that grow in threes at the tips of thin, reddish brown stems and small white flowers in the spring. It is an edible plant with medicinal properties, including soothing mouth sores and sore throat and alleviating cramps and nausea.
Oxalis Regnellii, Lucky Shamock
Oxalis regnellii, commonly called lucky shamrock and purple leaf oxalis, is a shamrock native to South America. The plant has large purple triangular leaves that grow in threes and white flowers all season long. Lucky shamrock needs partial shade and moist, well-drained soil with plenty of organic matter to grow well. It is an attractive plant in borders and rock gardens, as well as an easy-to-grow potted plant.
Oxalis Albicans, Hairy Woodsorrel
Oxalis albicans, commonly called hairy woodsorrel or white oxalis, is native to California, the Southwestern United States and northern Mexico. It is a small plant that grows up to 6 inches, and has fuzzy green, heart-shaped leaves in groups of three and small yellow flowers all season. The plant seeds profusely and sprouts easily, and is considered an invasive weed.
Oxalis Stricta, North American Woodsorrel
Oxalis stricta, North American woodsorrel or common yellow woodsorrel, is native to North America and Eurasia. It has yellow flowers and heart-shaped leaves that grow in groups of three at the tips of green stems. The leaves curl up at night and open during the day. It is a sour-tasting edible plant with medicinal properties, including alleviating stomach cramps and nausea and reducing fever. An orange dye is made from boiling the plant. North American woodsorrels need light, sandy soils and bright light and do not do well in the shade. It is a profuse seeder, making it a weedy plant.