Yellow Wood Sorrel is a perennial herb with trifoliate leaves and yellow flowers that is primarily a weed in greenhouses, container ornamentals, landscapes, turfgrass, and lawns. Leaves: Arranged alternately along the stem, long-petiolated, and divided into 3 heart-shaped leaflets. Leaf margins are smooth but fringed with hairs. Flowers occur in clusters that arise from long stalks at the leaf axils. Individual flowers consist of 5 yellow petals that are 4 to 9 mm long. Fruit: A capsule that is cylindrical and pointed with flat sides, sparsely hairy. Each capsule is approximately 3/4 inch long. Seed disperse from capsules by explosively ejecting up to 13 feet from the parent plant.