Oxalis illinoensis
 Oxalis illinoensis the Illinois Woodsorrel is a species of flowering plant in the woodsorrel family. It is native to the United States where it is endemic to the Interior Low Plateaus of Illinois Indiana Kentucky and Tennessee. The limits of the range of this species are unclear due to its similarity to Oxalis grandis with which there has been confusion.Oxalis illinoensis is a perennial that produces yellow flowers with red-lined centers.