Oxalis stricta, called the common yellow woodsorrel (or simply yellow woodsorrel), common yellow oxalis, upright yellow-sorrel, lemon clover, or more ambiguously and informally “sourgrass”  or “pickle plant“, is an herbaceous plant  native to North America, parts of Eurasia, and has 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 lays down, and branches regularly. It is not to be confused with similar plants which are also often referred to as “yellow woodsorrel”.
•Medicine: The leaves are chewed for nausea, and to relieve mouth sores and sore throats, and a poultice of fresh leaves for cancers and old sores. Leaf teas are brewed for fevers, urinary infections and scurvy.
•Note: Large doses may cause oxalate poisoning.