Pink wood sorrel. A wood sorrel is a chestnut horse of wood of course. You can find wood sorrel in a wooden barn, in wooden paddocks, and in wooden chestnut trees. All chestnut trees are wooden, unless you get a plastic one to go with your plastic Christmas tree.
Oxalis polyphylla var. heptaphylla is native to the cape of Africa. Common names include Many-leaved Wood Sorrel, Narrow-leaved Sorrel and Finger Sorrel. It is a winter growing bulb that goes dormant in the summer.