Plant Information

Plant Information

Orchids, Rare Illinois

For many of us, part of the joy of spring is heading out to the forest preserves and seeing the wildflowers in bloom. But for Susanne Masi, a plant conservationist at the Chicago Botanic Garden, the wildflowers she seeks we might never see, since they are listed as threatened or endangered by the state or federal government. All are rare, either due to loss of habitat, removal of fire from the ecosystem, or competition from invasive plants such as European buckthorn or purple loosestrife.


Susanne Masi has been gathering data on these species for the past year. This information will help to maintain their numbers and ensure their survival in the wild. She is assisted by more than 100 volunteers in a monitoring program called Plants of Concern, a joint program coordinated by the Chicago Botanic Garden and funded in part by Chicago Wilderness.


Of all the wildflowers monitored, some of the showiest are in the orchid family. "You think of orchids as tropical, not plants found in the Midwest," she said, "and yet we have 17 genera here in the Chicago area alone. The difference is that orchids are mainly arboreal in the tropics, but here they’re terrestrial. What makes orchids particularly interesting is the variety of their flowers. Each genus is different, with their flower shapes partly determined by the type of insect that pollinates them."


The showy lady slipper (Cypripedium reginae) is a rare orchid in the Chicago area but not yet monitored by Plants of Concern. Its large white-and-crimson-striped, pouchlike flower admits only tiny green bees, which are their pollinators. Other insects fail to get into the flower or become stuck between the sticky anthers. Sometimes called the "Queen Orchid of America" with its slipperlike pouch of vivid purple-pink and its three white, flared petals, it rivals the orchids of the tropics for beauty. It grows from 1 to 3 feet, in fens or bogs. Two other lady slippers, also rare in the Chicago area and pollinated by the tiny green bee, are the moccasin flower (Cypripedium acaule) and the small yellow lady slipper (Cypripedium calceolus var. parviflorum). The moccasin flower has a small, waxy, white pouchlike flower with green-purple sepals and petals extending outward and over. It grows up to 12 inches in wet prairies and boggy meadows. The yellow lady slipper, monitored by Plants of Concern, grows up to 2 feet with a showy yellow inflated lip nearly 2 inches long, and two spirally twisted side petals ranging in color from green to orange to brown. Looking to some like a "bright yellow Indian moccasin," it likes calcareous marshy habitats.


The snake-mouth orchid or rose pogonia (Pogonia ophioglossoides) is also a monitored plant. A beautiful pink or purple flower on a long slender stem, it has a fringed lower lip of yellow bristles designed to attract its main pollinator, the bumblebee. In the Chicago area it prefers fens and wet swales between dunes along the lakeshore. It reaches 16 inches, with one broad leaf sheathing the stem at midpoint. THE GRASS PINK A third endangered monitored orchid is the grass pink (Calapogon tuberosus), a delicate raceme of up to ten rose-pink to purple flowers found in the wet acid soil of bogs, peat meadows, and fens. This orchid grows to 18 inches and is described as "upside down," since the yellow crested lip is at the top of the flower whereas with most orchids, the hairy lip is at the bottom. These bristles mimic pollen-filled anthers that are so attractive to small bees.


Among the loveliest of the orchids of Illinois, but not yet monitored, is the purple fringed orchid (Platanthera psycodes), found in shady or sunny sites. The rose-purple or lavender-pink flowers are very showy, with 20 to 125 of them clustered in a cylinder at the top of the stalk. The lip of each flower is further divided into three fringed, fan-shaped segments. This orchid is pollinated by butterflies by day and moths by night. Only a few of the rare orchids are found locally. Orchids represent only one family of the 81 different species monitored by Plants of Concern volunteers at 91 different sites. As Masi says, "The more we learn about these plants, the better our chance of saving them from extinction." For more information on plant conservation science at the Garden, visit