Range and Habitat in Illinois
Yellow Lady's Slipper Orchid is an uncommon plant that is widely scattered across Illinois (see Distribution Map). It is less common than formerly, but still persists in small colonies at several sites. Habitats include mesic to dry deciduous woodlands, sandy woodlands and savannas, thinly wooded bluffs along rivers, and shady areas of bogs. The size of local populations can increase in response to fallen trees or occasional wildfires, as this reduces excessive shade from woody vegetation. Some authorities regard this orchid as a native variety of Cypripedium calceolus, which occurs in Eurasia. Under this system of classification, its scientific name is Cypripedium calceolus pubescens.