''Oxalis illinoensis'', the Illinois woodsorrel, is a species of flowering plant in the woodsorrel family (Oxalidaceae). It is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to the United States, where it found in Illinois, Indiana, Kentucky, and Tennessee. The limits of the range of this species are unclear due to its similarity to ''

Oxalis grandis ''Oxalis grandis,'' commonly known as great yellow woodsorrel or large yellow wood sorrel, is an annual plant and herb in the woodsorrel family. It is native to the eastern United States from Georgia north to Pennsylvania and Wisconsin, west as ...

'', with which there has been confusion."Again: Taxonomy of Yellow-Flowered Caulescent ''Oxalis'' (Oxalidaceae) in Eastern North America"
''J. Bot. Res. Inst. Texas'' 3(2): 727–738. 2009 ''Oxalis illinoensis'' is a perennial that produces yellow flowers with red-lined centers. Its primary habitat is

calcareous Calcareous () is an adjective meaning "mostly or partly composed of calcium carbonate", in other words, containing lime or being chalky. The term is used in a wide variety of scientific disciplines. In zoology ''Calcareous'' is used as an adje ...

forests and bluffs.

References

{{Taxonbar, from=Q15345323 illinoensis Endemic flora of the United States Plants described in 1982 Flora without expected TNC conservation status