Yellow Woodsorrel looks like a clover, with heart-shaped leaves that fold up during the night. Control. Yellow woodsorrel (Oxalis stricta) is an herbaceous perennial common in greenhouse and turf situations.It is most recognizable due to the heart-shaped leaflets that are found three to a leaf. Identifying Yellow Wood Sorrel. See below Description. It is considered a weed in many turf and garden areas and is also found in woodlands, meadows, disturbed areas. Description. Common yellow woodsorrel is in the Oxalidaceae family. 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 a herbaceous plant native to North America, parts of Eurasia, and has a rare introduction in Britain. The flowers are small and buttery yellow with five petals and the leaves grow in clusters. Common yellow woodsorrel is distinct from other wood sorrels in that the seed pods bend sharply upward on their stalks and the stalks also grow at a sharp angle from the main stalk (both angles are about 90 degrees). The plant has a shallow taproot, and hairy stems that are 4 to 10 inches tall. Yellow Woodsorrel; Yellow Wood Sorrel; Phonetic Spelling oks-AL-iss STRIK-tuh This plant has low severity poison characteristics. Oxalis or yellow woodsorrel (Oxalis stricta) is a common cool-season perennial weed that persists almost year-around in Southeastern lawns.It grows sporadically in landscape beds among shrubs and flowers, in vegetable gardens, and is known to pop up occasionally in container plantings. How can you tell if your weed is Yellow Woodsorrel? It also tends to grow in a more upright fashion than other wood sorrels (stricta means “upright”).