In biology, determination is the process of matching a specimen of an organism to a known taxon. Two native species, one common across the state of Illinois, the other seldom seen outside the southern Illinois lowlands, can be observed and enjoyed at Salt Creek Woods Nature Preserve in Westchester, Illinois. While I’m dropping a few clues, you will need some determination of the other kind to be in a position to make the identifications for yourself in the field. May fair conditions greet you!
Swamp Cypress Taxodium distichum Family: Cupressaceae
White Trout Lily Erythronium albidum Family: Liliaceae
The Cairn: An Outdoor Recreation Handbook 