Woodsorrel, Upright Yellow Woodsorrel (Xanthoxalis stricta), fam. Oxalidaceae.
A forest plant and city weed. Easily recognized by ternary leaves, each leaflet of those can fold in half.
Iron Cross, Lucky Clover, or Four-leaved Pink-Sorrel (Oxalis tetraphylla) – ornamental plant which leaves are four-lobed and have spots in the center.
